The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporat...The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was reported.Outstanding hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mV at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) samples.In the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co sites.It was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 V at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting voltage.It was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation.展开更多
Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air bat...Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air batteries.Although Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active sites.Motivated by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) sites.Such a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N precursors.Benefitting from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(vs.reversible hydrogen electrode(RHE)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 h.Molecular dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR performance.In situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C SAC-950.This work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties.展开更多
We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in...We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR.展开更多
The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To ad...The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To address such issue,herein,Fe-N_(x) sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution,thus enhancing the intrinsic catalytic activity.Precisely,atomically dispersed Fe-N_(x) sites supported on N/S-doped mesoporous carbon(NSC)coupled with FeS@C core-shell nanoparticles(FAS-NSC@950) is synthesized by a facile hydrothermal reaction and subsequent pyrolysis.Due to the presence of an in situ-grown conductive graphitic layer(shell),the FeS nanoparticles(core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling interactions.Consequently,FAS-NSC@950displays a more positive half-wave potential(E_(1/2)) of 0.871 V with a significantly boosted ORR kinetics(Tafel slope=52.2 mV dec^(-1)),outpacing the commercial Pt/C(E_(1/2)=0.84 V and Tafel slope=54.6 mV dec^(-1)).As a bifunctional electrocatalyst,it displays a smaller bifunctional activity parameter(ΔE) of 0.673 V,surpassing the Pt/C-RuO_(2) combination(ΔE=0.724 V).Besides,the FAS-NSC@950-based zincair battery(ZAB) displays superior power density,specific capacity,and long-term cycling performance to the Pt/C-Ir/C-based ZAB.This work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SACs for ORR,with potential implications for energy conversion and storage technologies.展开更多
The development of earth-abundant electrocatalysts with high performance for electrochemical CO_(2)reduction(ECR)is of great significance.Cu-based catalysts have been widely investigated for ECR due to their unique ab...The development of earth-abundant electrocatalysts with high performance for electrochemical CO_(2)reduction(ECR)is of great significance.Cu-based catalysts have been widely investigated for ECR due to their unique ability to generate various carbonaceous products,but directing selectivity toward one certain product and identifying the real active sites during ECR are still full of challenge.Here,after the incorporation of CdO into CuO,the Cu_(0.5)Cd_(0.5)-O catalyst achieves a 10.3-fold enhancement for CO selectivity in comparison with CuO,and a CO faradic efficiency nearly 90%with a current density around20 mA cm^(-2)could maintain at least 60 h.Interestingly,a wide CO/H_(2)ratio(0.07-10)is reached on Cu_(x)Cd_(1-x)-O catalysts by varying the Cu/Cd ratio,demonstrating the potential of syngas production using such catalysts.The results of ex situ XRD,XPS,and in situ Raman reveal that the real active sites of Cu_(0.5)Cd_(0.5)-O catalysts for CO production during ECR reaction are the reconstructed mixed phases of CuCd alloy and CdCO_(3).In situ FTIR and theoretical calculations further implicate the presence of Cd related species promotes the CO desorption and inhibits the H_(2)evolution,thus leading to an enhanced CO generation.展开更多
An in-depth mechanism in zonal activation of CO_(2)and H2molecular over dual-active sites has not been revealed yet.Here,Ni-Co-MgO was rationally constructed to elucidate the CO_(2)methanation mechanism.The abundant s...An in-depth mechanism in zonal activation of CO_(2)and H2molecular over dual-active sites has not been revealed yet.Here,Ni-Co-MgO was rationally constructed to elucidate the CO_(2)methanation mechanism.The abundant surface nickel and cobalt components as active sites led to strong Ni-Co interaction with charge transfer from nickel to cobalt.Notably,electron-enriched Coδ-species participated in efficient chemisorption and activation of CO_(2)to generate monodentate carbonate.Simultaneously,plentiful available Ni0sites facilitated H2dissociation,thus CO_(2)and H2were smoothly activated at zones of Coδ-species and Ni0,respectively.Detailed in situ DRIFTS,quasi situ XPS,TPSR,and DFT calculations substantiated a new formate evolution mechanism via monodentate carbonate instead of traditional bidentate carbonate based on synergistic catalysis of Coδ-species and Ni0.The zonal activation of CO_(2)and H2by tuning electron behaviors of double-center catalysts can boost heterogeneous catalytic hydrogenation performance.展开更多
The insufficient active sites and slow interfacial charge trans-fer of photocatalysts restrict the efficiency of CO_(2) photoreduction.The synchronized modulation of the above key issues is demanding and chal-lenging....The insufficient active sites and slow interfacial charge trans-fer of photocatalysts restrict the efficiency of CO_(2) photoreduction.The synchronized modulation of the above key issues is demanding and chal-lenging.Herein,strain-induced strategy is developed to construct the Bi–O-bonded interface in Cu porphyrin-based monoatomic layer(PML-Cu)and Bi_(12)O_(17)Br_(2)(BOB),which triggers the surface interface dual polarization of PML-Cu/BOB(PBOB).In this multi-step polarization,the built-in electric field formed between the interfaces induces the electron transfer from con-duction band(CB)of BOB to CB of PML-Cu and suppresses its reverse migration.Moreover,the surface polarization of PML-Cu further promotes the electron converge in Cu atoms.The introduction of PML-Cu endows a high density of dispersed Cu active sites on the surface of PBOB,significantly promoting the adsorption and activation of CO_(2) and CO desorption.The conversion rate of CO_(2) photoreduction to CO for PBOB can reach 584.3μmol g-1,which is 7.83 times higher than BOB and 20.01 times than PML-Cu.This work offers valuable insights into multi-step polarization regulation and active site design for catalysts.展开更多
The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)...The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)and phenol(PhOH)were used to prepare a novel class of deep eutectic solvents(DESs)with multiple active sites and low viscosities.The NH_(3) separation performance of EtOHACl+PhOH DESs was analyzed completely.It is figured out that the NH_(3) absorption rates in EtOHACl+PhOH DESs are very fast.The NH_(3) absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg1 at 11.2 and 100.4 kPa under 298.2 K,respectively.In addition,the EtOHACl+PhOH DESs present highly selective absorption of NH_(3) over N_(2) and H_(2) and good regenerative properties after seven cycles of absorption/desorption.The intrinsic separation mechanism of NH_(3) by EtOHACl+PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.展开更多
The high-temperature pyrolysis process for preparing M–N–C single-atom catalyst usually results in high heterogeneity in product structure concurrently contains multiscale metal phases from single atoms(SAs),atomic ...The high-temperature pyrolysis process for preparing M–N–C single-atom catalyst usually results in high heterogeneity in product structure concurrently contains multiscale metal phases from single atoms(SAs),atomic clusters to nanoparticles.Therefore,understanding the interactions among these components,especially the synergistic effects between single atomic sites and cluster sites,is crucial for improving the oxygen reduction reaction(ORR)activity of M–N–C catalysts.Accordingly,herein,we constructed a model catalyst composed of both atomically dispersed FeN4 SA sites and adjacent Fe clusters through a site occupation strategy.We found that the Fe clusters can optimize the adsorption strength of oxygen reduction intermediates on FeN4 SA sites by introducing electron-withdrawing–OH ligands and decreasing the d-band center of the Fe center.The as-developed catalyst exhibits encouraging ORR activity with halfwave potentials(E1/2)of 0.831 and 0.905 V in acidic and alkaline media,respectively.Moreover,the catalyst also represents excellent durability exceeding that of Fe–N–C SA catalyst.The practical application of Fe(Cd)–CNx catalyst is further validated by its superior activity and stability in a metalair battery device.Our work exhibits the great potential of synergistic effects between multiphase metal species for improvements of singleatom site catalysts.展开更多
Electrocatalytic oxygen reduction reaction(ORR)is one of the most important reactions in electrochemical energy technologies such as fuel cells and metal–O2/air batteries,etc.However,the essential catalysts to overco...Electrocatalytic oxygen reduction reaction(ORR)is one of the most important reactions in electrochemical energy technologies such as fuel cells and metal–O2/air batteries,etc.However,the essential catalysts to overcome its slow reaction kinetic always undergo a complex dynamic evolution in the actual catalytic process,and the concomitant intermediates and catalytic products also occur continuous conversion and reconstruction.This makes them difficult to be accurately captured,making the identification of ORR active sites and the elucidation of ORR mechanisms difficult.Thus,it is necessary to use extensive in-situ characterization techniques to proceed the real-time monitoring of the catalyst structure and the evolution state of intermediates and products during ORR.This work reviews the major advances in the use of various in-situ techniques to characterize the catalytic processes of various catalysts.Specifically,the catalyst structure evolutions revealed directly by in-situ techniques are systematically summarized,such as phase,valence,electronic transfer,coordination,and spin states varies.In-situ revelation of intermediate adsorption/desorption behavior,and the real-time monitoring of the product nucleation,growth,and reconstruction evolution are equally emphasized in the discussion.Other interference factors,as well as in-situ signal assignment with the aid of theoretical calculations,are also covered.Finally,some major challenges and prospects of in-situ techniques for future catalysts research in the ORR process are proposed.展开更多
Lithium-sulfur(Li-S)batteries with high theoretical energy density are promising advanced energy storage devices.However,shuttling of dissolute lithium polysulfide(LiPSs)and sluggish conversion kinetics impede their a...Lithium-sulfur(Li-S)batteries with high theoretical energy density are promising advanced energy storage devices.However,shuttling of dissolute lithium polysulfide(LiPSs)and sluggish conversion kinetics impede their applications.Herein,single nickel(Ni)atoms on two-dimensional(2D)nitrogen(N)-doped carbon with Ni-N_(4)-O overcoordinated structure(SANi-N_(4)-O/NC)are prepared and firstly used as a sulfur host of Li-S batteries.Due to the efficient polysulfides traps and highly LiPSs conversion effect of SANi-N_(4)-O/NC,the electrochemical performance of Li-S batteries obviously improved.The batteries can well operate even under high sulfur loading(5.8 mg cm^(-2))and lean electrolyte(6.1μL mg^(-1))condition.Meanwhile,density functional theory(DFT)calculations demonstrate that Ni single atom’s active sites decrease the energy barriers of conversion reactions from Li_(2)S_(8)to Li2S due to the strong interaction between SANi-N_(4)-O/NC and LiPSs.Thus,the kinetic conversion of LiPSs was accelerated and the shuttle effect is suppressed on SANi-N_(4)-O/NC host.This study provides a new design strategy for a 2D structure with single-atom overcoordinated active sites to facilitate the fast kinetic conversion of LiPSs for Li-S cathode.展开更多
On October 26,2022,the International Union of Geological Sciences(IUGS)unveiled the First 100 IUGS Geological Heritage Sites in Spain.These sites are located in56 countries,including 34 in the Americas,28 in Europe,15...On October 26,2022,the International Union of Geological Sciences(IUGS)unveiled the First 100 IUGS Geological Heritage Sites in Spain.These sites are located in56 countries,including 34 in the Americas,28 in Europe,15 in Africa and 23 in the Asia-Pacific-Middle East region(Table 1).The seven selected sites of China are introduced as follows(black font in Table 1).展开更多
Metal-organic frameworks(MOFs) are becoming more and more popular as the fillers in polymer electrolytes in recent years. In this study, a series of MOFs(NH_(2)-MIL-101(Fe), MIL-101(Fe), activated NH_(2)-MIL-101(Fe) a...Metal-organic frameworks(MOFs) are becoming more and more popular as the fillers in polymer electrolytes in recent years. In this study, a series of MOFs(NH_(2)-MIL-101(Fe), MIL-101(Fe), activated NH_(2)-MIL-101(Fe) and activated MIL-101(Fe)) were synthesized and added to PEO-based solid composite electrolytes(SCEs). Furthermore, the role of the —NH_(2) groups and open metal sites(OMSs) were both examined. Different ratios of MOFs vs polymers were also studied by the electrochemical characterizations. At last, we successfully designed a novel solid composite electrolyte containing activated NH_(2)-MIL-101(Fe),PEO, Li TFSI and PVDF for the high-performance all-solid-state lithium-metal batteries. This work might provide new insight to understand the interactions between polymers and functional groups or OMSs of MOFs better.展开更多
The electronic and functional synergies between the twin metal centers make dual single-atom catalysts(DACs) attractive for oxygen electrocatalysis. The catalytic activities of DACs are largely decided by their surrou...The electronic and functional synergies between the twin metal centers make dual single-atom catalysts(DACs) attractive for oxygen electrocatalysis. The catalytic activities of DACs are largely decided by their surrounding micro-environment and supporting substrates. Modulating the micro-environment as well as engineering the efficient support is challenging tasks. Moreover, both are critical to optimizing the performance of DACs. Herein, a novel bio-cooperative strategy is developed to synthesize Fe Ni-DAC wherein Fe-Ni dual-atom sites are embedded in the N, P codoped tyre shaped carbon matrix. The configuration matching of Fe-Ni dual centers together with the local electronic engineering of N, P heteroatoms synergistically boost the catalytic activity on the oxygen reaction. Furthermore, the central-hollow highlyporous carbon matrix not only gives rise to a large amount of active sites, but also facilitates fast kinetics.Taking advantage of both the DAC and the substrate, the Fe Ni-NPC hollow tyre(HT) catalyst scores high in both oxygen reduction and evolution reactions, which exhibits the narrow potential difference and excellent durability. The aqueous Zn-air full battery(ZAB) integrating the Fe Ni-NPC HT air cathode has a high power density and a good stability over long-term cycling. Moreover, the flexible solid-state ZAB assembled with the polymer electrolyte obtains the high reliability over a wide range of temperatures or under diverse outside deformations. Therefore, this work offers a new green approach to prepare highly efficient DACs with built-in modulated micro-environment and tailor-made substrates. Moreover,it also paves a new way to develop highly-pliable power source for flexible electronics.展开更多
Carbon-based N-coordinated Mn(Mn-N_(x)/C)single-atom electrocatalysts are considered as one of the most desirable non-precious oxygen reduction reaction(ORR)candidates due to their insignificant Fenton reactivity,high...Carbon-based N-coordinated Mn(Mn-N_(x)/C)single-atom electrocatalysts are considered as one of the most desirable non-precious oxygen reduction reaction(ORR)candidates due to their insignificant Fenton reactivity,high abundance,and intriguing electrocatalytic performance.However,current MnN_(x)/C single-atom electrocatalysts suffer from high overpotentials because of their low intrinsic activity and unsatisfactory chemical stability.Herein,through an in-situ polymerization-assisted pyrolysis,the Co as a second metal is introduced into the Mn-N_(x)/C system to construct Co,Mn-N_(x)dual-metallic sites,which atomically disperse in N-doped 1D carbon nanorods,denoted as Co,Mn-N/CNR and hereafter.Using electron microscopy and X-ray absorption spectroscopy(XAS)techniques,we verify the uniform dispersion of CoN4and MnN4atomic sites and confirm the effect of Co doping on the MnN_(4) electronic structure.Density functional theory(DFT)calculations further elucidate that the energy barrier of ratedetermining step(^(*)OH desorption)decreases over the 2 N-bridged MnCoN_(6) moieties related to the pure MnN_(4).This work provides an effective strategy to modulate the local coordination environment and electronic structure of MnN_(4) active sites for improving their ORR activity and stability.展开更多
Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li util...Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li utilization.Inducing uniform Li plating/stripping is the core of solving these problems.Herein,we design a highly lithiophilic carbon film with an outer sheath of the nanoneedle arrays to induce homogeneous Li plating/stripping.The excellent conductivity and 3D framework of the carbon film not only offer fast charge transport across the entire electrode but also mitigate the volume change of Li metal during cycling.The abundant lithiophilic sites ensure stable Li plating/stripping,thereby inhibiting the Li dendritic growth and"dead"Li formation.The resulting composite anode allows for stable Li stripping/plating under 0.5 mA cm^(-2) with a capacity of 0.5 mA h cm^(-2) for 4000 h and 3 mA cm^(-2) with a capacity of3 mA h cm^(-2) for 1000 h.The Ex-SEM analysis reveals that lithiophilic property is different at the bottom,top,or channel in the structu re,which can regulate a bottom-up uniform Li deposition behavior.Full cells paired with LFP show a stable capacity of 155 mA h g^(-1) under a current density of 0.5C.The pouch cell can keep powering light-emitting diode even under 180°bending,suggesting its good flexibility and great practical applications.展开更多
Atomically dispersed metal sites(ADMSs)play key roles in electrochemical energy conversion.The covalent organic frameworks(COFs)enable the precise control of the chemical compositions and structures at the molecular l...Atomically dispersed metal sites(ADMSs)play key roles in electrochemical energy conversion.The covalent organic frameworks(COFs)enable the precise control of the chemical compositions and structures at the molecular level,making them ideal substrates for supporting ADMSs.In this review,we systematically summarize the recent progress on the design and synthesis of ADMSs in COFs,including embedding molecular catalysts into COFs,immobilizing ADMSs on heteroatom-containing COFs,and preparing COF-derived carbon materials through pyrolysis.The electrocatalytic performance of the resulting catalysts is presented for various electrochemical reactions,involving oxygen reduction reaction(ORR),carbon dioxide reduction reaction(CO_(2)RR),oxygen evolution reaction(OER),hydrogen evolution reaction(HER),and nitrogen reduction reaction(NRR).The modulation strategies of AMDSs in COFs for enhanced activity,selectivity,and stability are highlighted,together with a perspective of the current challenges and the future opportunities in this field.展开更多
The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,wh...The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,while the challenge associated with N_(2) activation highlights the demand for efficient electrocatalysts.Herein,we demonstrate that PdCu nanoparticles with different Pd/Cu ratios anchored on boron nanosheet(PdCu/B)behave as efficient NRR electrocatalysts toward NH_(3) synthesis.Theoretical and experimental results confirm that the highly efficient NH_(3) synthesis can be achieved by regulating the charge transfer between interfaces and forming a symmetry-breaking site,which not only alleviates the hydrogen evolution but also changes the adsorption configuration of N_(2) and thus optimizes the reaction pathway of NRR over the separated Pd sites.Compared with monometallic Pd/B and Cu/B,the PdCu/B with the optimized Pd/Cu ratio of 1 exhibits superior activity and selectivity for NH_(3) synthesis.This study provides new insight into developing efficient catalysts for small energy molecule catalytic conversion via regulating the charge transfer between interfaces and constructing symmetry-breaking sites.展开更多
Atmospheric CO_(2)concentrations are soaring due to the continued use of fossil fuels in energy production,an anthropogenic activity that is playing a leading role in global warming.Thus,research aimed at the capture ...Atmospheric CO_(2)concentrations are soaring due to the continued use of fossil fuels in energy production,an anthropogenic activity that is playing a leading role in global warming.Thus,research aimed at the capture and conversion of CO_(2)into value-added products,such as cyclic carbonates,is booming.While CO_(2)is an abundant,cheap,non-toxic,and readily accessible Cl feedstock,its thermodynamic stability necessitates the development of highly efficient catalysts that are able to promote chemical reactions under mild conditions.In this work,a novel mesoporous poly(ionic liquid)with dual active sites was synthesized through a facile method that involves co-polymerization,post-synthetic metalation,and supercritical CO_(2)drying.Due to a high density of nucleophilic and electrophilic sites,the as-prepared poly(ionic liquid),denoted as P2D-4BrBQA-Zn,offers excellent performance in a CO_(2)cycloaddition reaction using epichlorohydrin as the substrate(98.9%conversion and 96.9%selectivity).Moreover the reaction is carried out under mild,solvent-free,and additive-free conditions.Notably,P2D-4BrBQA-Zn also efficiently promotes the conversion of various other epoxide substrates into cyclic carbonates.Overall,the catalyst is found to have excellent substrate compatibility,stability,and recyclability.展开更多
基金the financial support of the Doctoral Research Initiation Foundation of Linyi University(LYDX2020BS016)the National Natural Science Foundation of Shandong Province(ZR2021QB208,ZR2022MB054)+4 种基金the National Natural Science Foundation of China(22305262)SIAT Innovation Program for Excellent Young Researchers(2022)Shenzhen Science and Technology Program Grant(RCJC20200714114435061,ZDSYS20220527171406014)the City University of Hong Kong Donation Research Grants(9220061 and 9229021)City University of Hong Kong Strategic Research Grant(SRG 7005505)。
文摘The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was reported.Outstanding hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mV at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) samples.In the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co sites.It was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 V at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting voltage.It was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation.
基金financially supported by the National Key R&D Program of China(2022YFB4004100)the National Natural Science Foundation of China(22272161)+6 种基金the Jilin Province Science and Technology Development Program(20230101367JC)financially supported by the National Natural Science Foundation of China(22073094)the Science and Technology Development Program of Jilin Province(20210402059GH)the Science and Technology Plan Projects of Yunnan Province(202101BC070001–007)the Major Science and Technology Projects for Independent Innovation of China FAW Group Co.,Ltd(20220301018GX)the essential support of the Network and Computing Center,CIAC,CASthe Computing Center of Jilin Province。
文摘Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air batteries.Although Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active sites.Motivated by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) sites.Such a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N precursors.Benefitting from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(vs.reversible hydrogen electrode(RHE)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 h.Molecular dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR performance.In situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C SAC-950.This work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties.
基金the Natural Science Foundation of China(11922415,12274471)Guangdong Basic and Applied Basic Research Foundation(2022A1515011168,2019A1515011718,2019A1515011337)the Key Research and Development Program of Guangdong Province,China(2019B110209003).
文摘We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR.
基金financially supported by the National Natural Science Foundation of China(21773024)the Natural Science Foundation of Sichuan Province of China(2023NSFC0084)the China Postdoctoral Science Foundation(2019M663469)。
文摘The development of efficient single-atom catalysts(SACs) for the oxygen reduction reaction(ORR)remains a formidable challenge,primarily due to the symmetric charge distribution of metal singleatom sites(M-N_(4)).To address such issue,herein,Fe-N_(x) sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution,thus enhancing the intrinsic catalytic activity.Precisely,atomically dispersed Fe-N_(x) sites supported on N/S-doped mesoporous carbon(NSC)coupled with FeS@C core-shell nanoparticles(FAS-NSC@950) is synthesized by a facile hydrothermal reaction and subsequent pyrolysis.Due to the presence of an in situ-grown conductive graphitic layer(shell),the FeS nanoparticles(core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling interactions.Consequently,FAS-NSC@950displays a more positive half-wave potential(E_(1/2)) of 0.871 V with a significantly boosted ORR kinetics(Tafel slope=52.2 mV dec^(-1)),outpacing the commercial Pt/C(E_(1/2)=0.84 V and Tafel slope=54.6 mV dec^(-1)).As a bifunctional electrocatalyst,it displays a smaller bifunctional activity parameter(ΔE) of 0.673 V,surpassing the Pt/C-RuO_(2) combination(ΔE=0.724 V).Besides,the FAS-NSC@950-based zincair battery(ZAB) displays superior power density,specific capacity,and long-term cycling performance to the Pt/C-Ir/C-based ZAB.This work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SACs for ORR,with potential implications for energy conversion and storage technologies.
基金financially supported by the National Natural Science Foundation of China with grant number of 22172082 and 21978137。
文摘The development of earth-abundant electrocatalysts with high performance for electrochemical CO_(2)reduction(ECR)is of great significance.Cu-based catalysts have been widely investigated for ECR due to their unique ability to generate various carbonaceous products,but directing selectivity toward one certain product and identifying the real active sites during ECR are still full of challenge.Here,after the incorporation of CdO into CuO,the Cu_(0.5)Cd_(0.5)-O catalyst achieves a 10.3-fold enhancement for CO selectivity in comparison with CuO,and a CO faradic efficiency nearly 90%with a current density around20 mA cm^(-2)could maintain at least 60 h.Interestingly,a wide CO/H_(2)ratio(0.07-10)is reached on Cu_(x)Cd_(1-x)-O catalysts by varying the Cu/Cd ratio,demonstrating the potential of syngas production using such catalysts.The results of ex situ XRD,XPS,and in situ Raman reveal that the real active sites of Cu_(0.5)Cd_(0.5)-O catalysts for CO production during ECR reaction are the reconstructed mixed phases of CuCd alloy and CdCO_(3).In situ FTIR and theoretical calculations further implicate the presence of Cd related species promotes the CO desorption and inhibits the H_(2)evolution,thus leading to an enhanced CO generation.
基金funded by the Science and Technology Project of Southwest United Graduate School of Yunnan Province(No.202302AQ370002)the National Natural Science Foundation of China(No.22206066)。
文摘An in-depth mechanism in zonal activation of CO_(2)and H2molecular over dual-active sites has not been revealed yet.Here,Ni-Co-MgO was rationally constructed to elucidate the CO_(2)methanation mechanism.The abundant surface nickel and cobalt components as active sites led to strong Ni-Co interaction with charge transfer from nickel to cobalt.Notably,electron-enriched Coδ-species participated in efficient chemisorption and activation of CO_(2)to generate monodentate carbonate.Simultaneously,plentiful available Ni0sites facilitated H2dissociation,thus CO_(2)and H2were smoothly activated at zones of Coδ-species and Ni0,respectively.Detailed in situ DRIFTS,quasi situ XPS,TPSR,and DFT calculations substantiated a new formate evolution mechanism via monodentate carbonate instead of traditional bidentate carbonate based on synergistic catalysis of Coδ-species and Ni0.The zonal activation of CO_(2)and H2by tuning electron behaviors of double-center catalysts can boost heterogeneous catalytic hydrogenation performance.
基金This work was supported by the National Natural Science Foundation of China(Nos.22138011,22205108,22378206)Open Research Fund of Key Laboratory of the Ministry of Education for Advanced Catalysis Materials and Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces(KLMEACM 202201),Zhejiang Normal University.
文摘The insufficient active sites and slow interfacial charge trans-fer of photocatalysts restrict the efficiency of CO_(2) photoreduction.The synchronized modulation of the above key issues is demanding and chal-lenging.Herein,strain-induced strategy is developed to construct the Bi–O-bonded interface in Cu porphyrin-based monoatomic layer(PML-Cu)and Bi_(12)O_(17)Br_(2)(BOB),which triggers the surface interface dual polarization of PML-Cu/BOB(PBOB).In this multi-step polarization,the built-in electric field formed between the interfaces induces the electron transfer from con-duction band(CB)of BOB to CB of PML-Cu and suppresses its reverse migration.Moreover,the surface polarization of PML-Cu further promotes the electron converge in Cu atoms.The introduction of PML-Cu endows a high density of dispersed Cu active sites on the surface of PBOB,significantly promoting the adsorption and activation of CO_(2) and CO desorption.The conversion rate of CO_(2) photoreduction to CO for PBOB can reach 584.3μmol g-1,which is 7.83 times higher than BOB and 20.01 times than PML-Cu.This work offers valuable insights into multi-step polarization regulation and active site design for catalysts.
基金supported by the National Natural Science Foundation of China(22221005 and 22008033).
文摘The efficient separation and collection of ammonia(NH_(3))during NH_(3) synthesis process is essential to improve the economic efficiency and protect the environment.In this work,ethanolammonium hydrochloride(EtOHACl)and phenol(PhOH)were used to prepare a novel class of deep eutectic solvents(DESs)with multiple active sites and low viscosities.The NH_(3) separation performance of EtOHACl+PhOH DESs was analyzed completely.It is figured out that the NH_(3) absorption rates in EtOHACl+PhOH DESs are very fast.The NH_(3) absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg1 at 11.2 and 100.4 kPa under 298.2 K,respectively.In addition,the EtOHACl+PhOH DESs present highly selective absorption of NH_(3) over N_(2) and H_(2) and good regenerative properties after seven cycles of absorption/desorption.The intrinsic separation mechanism of NH_(3) by EtOHACl+PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.
基金supported by the National Natural Science Foundation of China(22109100,22075203)Guangdong Basic and Applied Basic Research Foundation(2022A1515011677)+1 种基金Shenzhen Science and Technology Project Program(JCYJ2021032409420401)Natural Science Foundation of SZU(000002111605).
文摘The high-temperature pyrolysis process for preparing M–N–C single-atom catalyst usually results in high heterogeneity in product structure concurrently contains multiscale metal phases from single atoms(SAs),atomic clusters to nanoparticles.Therefore,understanding the interactions among these components,especially the synergistic effects between single atomic sites and cluster sites,is crucial for improving the oxygen reduction reaction(ORR)activity of M–N–C catalysts.Accordingly,herein,we constructed a model catalyst composed of both atomically dispersed FeN4 SA sites and adjacent Fe clusters through a site occupation strategy.We found that the Fe clusters can optimize the adsorption strength of oxygen reduction intermediates on FeN4 SA sites by introducing electron-withdrawing–OH ligands and decreasing the d-band center of the Fe center.The as-developed catalyst exhibits encouraging ORR activity with halfwave potentials(E1/2)of 0.831 and 0.905 V in acidic and alkaline media,respectively.Moreover,the catalyst also represents excellent durability exceeding that of Fe–N–C SA catalyst.The practical application of Fe(Cd)–CNx catalyst is further validated by its superior activity and stability in a metalair battery device.Our work exhibits the great potential of synergistic effects between multiphase metal species for improvements of singleatom site catalysts.
基金the National Natural Science Foundation of China(No.52072256)Shanxi Science and Technology Major Project(No.20201101016)+1 种基金Key R&D program of Shanxi Province(No.202102030201006)Research Project Supported by Shanxi Scholarship Council of China(HGKY2019031).
文摘Electrocatalytic oxygen reduction reaction(ORR)is one of the most important reactions in electrochemical energy technologies such as fuel cells and metal–O2/air batteries,etc.However,the essential catalysts to overcome its slow reaction kinetic always undergo a complex dynamic evolution in the actual catalytic process,and the concomitant intermediates and catalytic products also occur continuous conversion and reconstruction.This makes them difficult to be accurately captured,making the identification of ORR active sites and the elucidation of ORR mechanisms difficult.Thus,it is necessary to use extensive in-situ characterization techniques to proceed the real-time monitoring of the catalyst structure and the evolution state of intermediates and products during ORR.This work reviews the major advances in the use of various in-situ techniques to characterize the catalytic processes of various catalysts.Specifically,the catalyst structure evolutions revealed directly by in-situ techniques are systematically summarized,such as phase,valence,electronic transfer,coordination,and spin states varies.In-situ revelation of intermediate adsorption/desorption behavior,and the real-time monitoring of the product nucleation,growth,and reconstruction evolution are equally emphasized in the discussion.Other interference factors,as well as in-situ signal assignment with the aid of theoretical calculations,are also covered.Finally,some major challenges and prospects of in-situ techniques for future catalysts research in the ORR process are proposed.
基金financial support from the National Natural Science Foundation of China(21878270,21878267,21922811,21978258 and 21961160742)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2019R01006)+3 种基金the Zhejiang Provincial Natural Science Foundation of China(LR19B060002)the Fundamental Research Funds for the Central Universities(2020XZZX002-09)the Startup Foundation for Hundred-Talent Program of Zhejiang Universitythe Zhejiang Key Laboratory of Marine Materials and Protective Technologies(2020K10)。
文摘Lithium-sulfur(Li-S)batteries with high theoretical energy density are promising advanced energy storage devices.However,shuttling of dissolute lithium polysulfide(LiPSs)and sluggish conversion kinetics impede their applications.Herein,single nickel(Ni)atoms on two-dimensional(2D)nitrogen(N)-doped carbon with Ni-N_(4)-O overcoordinated structure(SANi-N_(4)-O/NC)are prepared and firstly used as a sulfur host of Li-S batteries.Due to the efficient polysulfides traps and highly LiPSs conversion effect of SANi-N_(4)-O/NC,the electrochemical performance of Li-S batteries obviously improved.The batteries can well operate even under high sulfur loading(5.8 mg cm^(-2))and lean electrolyte(6.1μL mg^(-1))condition.Meanwhile,density functional theory(DFT)calculations demonstrate that Ni single atom’s active sites decrease the energy barriers of conversion reactions from Li_(2)S_(8)to Li2S due to the strong interaction between SANi-N_(4)-O/NC and LiPSs.Thus,the kinetic conversion of LiPSs was accelerated and the shuttle effect is suppressed on SANi-N_(4)-O/NC host.This study provides a new design strategy for a 2D structure with single-atom overcoordinated active sites to facilitate the fast kinetic conversion of LiPSs for Li-S cathode.
文摘On October 26,2022,the International Union of Geological Sciences(IUGS)unveiled the First 100 IUGS Geological Heritage Sites in Spain.These sites are located in56 countries,including 34 in the Americas,28 in Europe,15 in Africa and 23 in the Asia-Pacific-Middle East region(Table 1).The seven selected sites of China are introduced as follows(black font in Table 1).
基金financially supported by National Natural Science Foundation of China (21701083)Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX20_3137)。
文摘Metal-organic frameworks(MOFs) are becoming more and more popular as the fillers in polymer electrolytes in recent years. In this study, a series of MOFs(NH_(2)-MIL-101(Fe), MIL-101(Fe), activated NH_(2)-MIL-101(Fe) and activated MIL-101(Fe)) were synthesized and added to PEO-based solid composite electrolytes(SCEs). Furthermore, the role of the —NH_(2) groups and open metal sites(OMSs) were both examined. Different ratios of MOFs vs polymers were also studied by the electrochemical characterizations. At last, we successfully designed a novel solid composite electrolyte containing activated NH_(2)-MIL-101(Fe),PEO, Li TFSI and PVDF for the high-performance all-solid-state lithium-metal batteries. This work might provide new insight to understand the interactions between polymers and functional groups or OMSs of MOFs better.
基金supported by the Innovation Foundation of Graduate Student of Harbin Normal University (HSDSSCX2022-111)the Natural Science Foundation of Heilongjiang Province of China(TD2020B001)the Opening Project of State Key Laboratory of Advanced Chemical Power Sources (SKL-ACPS-C-25)。
文摘The electronic and functional synergies between the twin metal centers make dual single-atom catalysts(DACs) attractive for oxygen electrocatalysis. The catalytic activities of DACs are largely decided by their surrounding micro-environment and supporting substrates. Modulating the micro-environment as well as engineering the efficient support is challenging tasks. Moreover, both are critical to optimizing the performance of DACs. Herein, a novel bio-cooperative strategy is developed to synthesize Fe Ni-DAC wherein Fe-Ni dual-atom sites are embedded in the N, P codoped tyre shaped carbon matrix. The configuration matching of Fe-Ni dual centers together with the local electronic engineering of N, P heteroatoms synergistically boost the catalytic activity on the oxygen reaction. Furthermore, the central-hollow highlyporous carbon matrix not only gives rise to a large amount of active sites, but also facilitates fast kinetics.Taking advantage of both the DAC and the substrate, the Fe Ni-NPC hollow tyre(HT) catalyst scores high in both oxygen reduction and evolution reactions, which exhibits the narrow potential difference and excellent durability. The aqueous Zn-air full battery(ZAB) integrating the Fe Ni-NPC HT air cathode has a high power density and a good stability over long-term cycling. Moreover, the flexible solid-state ZAB assembled with the polymer electrolyte obtains the high reliability over a wide range of temperatures or under diverse outside deformations. Therefore, this work offers a new green approach to prepare highly efficient DACs with built-in modulated micro-environment and tailor-made substrates. Moreover,it also paves a new way to develop highly-pliable power source for flexible electronics.
基金the financial support from the Research Foundation for Talented Scholars of Hainan University(YEAZ22091)the financial supports from the Joint Funds of the National Natural Science Foundation of China(ZK20180055)+1 种基金the Programs for Foreign Talent(G2021106012L)the National Natural Science Foundation of China(22075290)。
文摘Carbon-based N-coordinated Mn(Mn-N_(x)/C)single-atom electrocatalysts are considered as one of the most desirable non-precious oxygen reduction reaction(ORR)candidates due to their insignificant Fenton reactivity,high abundance,and intriguing electrocatalytic performance.However,current MnN_(x)/C single-atom electrocatalysts suffer from high overpotentials because of their low intrinsic activity and unsatisfactory chemical stability.Herein,through an in-situ polymerization-assisted pyrolysis,the Co as a second metal is introduced into the Mn-N_(x)/C system to construct Co,Mn-N_(x)dual-metallic sites,which atomically disperse in N-doped 1D carbon nanorods,denoted as Co,Mn-N/CNR and hereafter.Using electron microscopy and X-ray absorption spectroscopy(XAS)techniques,we verify the uniform dispersion of CoN4and MnN4atomic sites and confirm the effect of Co doping on the MnN_(4) electronic structure.Density functional theory(DFT)calculations further elucidate that the energy barrier of ratedetermining step(^(*)OH desorption)decreases over the 2 N-bridged MnCoN_(6) moieties related to the pure MnN_(4).This work provides an effective strategy to modulate the local coordination environment and electronic structure of MnN_(4) active sites for improving their ORR activity and stability.
基金supported by the National Natural Science Foundation of China(31870570)the Science and Technology Plan of Fujian Provincial,China(2020H4026,2022G02020 and 2022H6002)+1 种基金the Science and Technology Plan of Xiamen(3502Z20203005)the Scientific Research Start-up Funding for Special Professor of Minjiang Scholars。
文摘Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li utilization.Inducing uniform Li plating/stripping is the core of solving these problems.Herein,we design a highly lithiophilic carbon film with an outer sheath of the nanoneedle arrays to induce homogeneous Li plating/stripping.The excellent conductivity and 3D framework of the carbon film not only offer fast charge transport across the entire electrode but also mitigate the volume change of Li metal during cycling.The abundant lithiophilic sites ensure stable Li plating/stripping,thereby inhibiting the Li dendritic growth and"dead"Li formation.The resulting composite anode allows for stable Li stripping/plating under 0.5 mA cm^(-2) with a capacity of 0.5 mA h cm^(-2) for 4000 h and 3 mA cm^(-2) with a capacity of3 mA h cm^(-2) for 1000 h.The Ex-SEM analysis reveals that lithiophilic property is different at the bottom,top,or channel in the structu re,which can regulate a bottom-up uniform Li deposition behavior.Full cells paired with LFP show a stable capacity of 155 mA h g^(-1) under a current density of 0.5C.The pouch cell can keep powering light-emitting diode even under 180°bending,suggesting its good flexibility and great practical applications.
基金supported by the National Natural Science Funds(No.21878226)Innovative Research Group Project of the National Natural Science Foundation of China(No.22121004)。
文摘Atomically dispersed metal sites(ADMSs)play key roles in electrochemical energy conversion.The covalent organic frameworks(COFs)enable the precise control of the chemical compositions and structures at the molecular level,making them ideal substrates for supporting ADMSs.In this review,we systematically summarize the recent progress on the design and synthesis of ADMSs in COFs,including embedding molecular catalysts into COFs,immobilizing ADMSs on heteroatom-containing COFs,and preparing COF-derived carbon materials through pyrolysis.The electrocatalytic performance of the resulting catalysts is presented for various electrochemical reactions,involving oxygen reduction reaction(ORR),carbon dioxide reduction reaction(CO_(2)RR),oxygen evolution reaction(OER),hydrogen evolution reaction(HER),and nitrogen reduction reaction(NRR).The modulation strategies of AMDSs in COFs for enhanced activity,selectivity,and stability are highlighted,together with a perspective of the current challenges and the future opportunities in this field.
基金National Key R&D Program of China,Grant/Award Number:2020YFA0710000National Natural Science Foundation of China,Grant/Award Numbers:22008170,21978200,22161142002,22121004。
文摘The Haber-Bosch process for industrial NH_(3) production is energy-intensive with heavy CO_(2) emissions.Electrochemical N_(2) reduction reaction(NRR)is an attractive carbon-neutral alternative for NH_(3) synthesis,while the challenge associated with N_(2) activation highlights the demand for efficient electrocatalysts.Herein,we demonstrate that PdCu nanoparticles with different Pd/Cu ratios anchored on boron nanosheet(PdCu/B)behave as efficient NRR electrocatalysts toward NH_(3) synthesis.Theoretical and experimental results confirm that the highly efficient NH_(3) synthesis can be achieved by regulating the charge transfer between interfaces and forming a symmetry-breaking site,which not only alleviates the hydrogen evolution but also changes the adsorption configuration of N_(2) and thus optimizes the reaction pathway of NRR over the separated Pd sites.Compared with monometallic Pd/B and Cu/B,the PdCu/B with the optimized Pd/Cu ratio of 1 exhibits superior activity and selectivity for NH_(3) synthesis.This study provides new insight into developing efficient catalysts for small energy molecule catalytic conversion via regulating the charge transfer between interfaces and constructing symmetry-breaking sites.
基金financial support from the National Natural Science Foundation of China(22078274,21903066)。
文摘Atmospheric CO_(2)concentrations are soaring due to the continued use of fossil fuels in energy production,an anthropogenic activity that is playing a leading role in global warming.Thus,research aimed at the capture and conversion of CO_(2)into value-added products,such as cyclic carbonates,is booming.While CO_(2)is an abundant,cheap,non-toxic,and readily accessible Cl feedstock,its thermodynamic stability necessitates the development of highly efficient catalysts that are able to promote chemical reactions under mild conditions.In this work,a novel mesoporous poly(ionic liquid)with dual active sites was synthesized through a facile method that involves co-polymerization,post-synthetic metalation,and supercritical CO_(2)drying.Due to a high density of nucleophilic and electrophilic sites,the as-prepared poly(ionic liquid),denoted as P2D-4BrBQA-Zn,offers excellent performance in a CO_(2)cycloaddition reaction using epichlorohydrin as the substrate(98.9%conversion and 96.9%selectivity).Moreover the reaction is carried out under mild,solvent-free,and additive-free conditions.Notably,P2D-4BrBQA-Zn also efficiently promotes the conversion of various other epoxide substrates into cyclic carbonates.Overall,the catalyst is found to have excellent substrate compatibility,stability,and recyclability.