Trimetallic palladium-copper-cobalt nanoparticles supported on reduced graphene oxide(PdCuCo/RGO)with different molar ratios of Pd,Cu and Co can be synthesized by facile chemical reduction with NaBH_4 as reductant and...Trimetallic palladium-copper-cobalt nanoparticles supported on reduced graphene oxide(PdCuCo/RGO)with different molar ratios of Pd,Cu and Co can be synthesized by facile chemical reduction with NaBH_4 as reductant and cetrimonium bromide as stabilizer.The morphology,structure and composition of the as-synthesized catalysts are characterized by transmission electron microscopy,X-ray diffraction and Xray photoelectron spectroscopy.The cyclic voltammetry and chronoamperometry are utilized to investigate the electrochemical activities and stabilities of the as-obtained catalysts.The results demonstrate that the PdCuCo/RGO catalyst shows superior catalytic activity and stability for methanol electrooxidation in alkaline media compared with PdCu/RGO,PdCo/RGO,and Pd/RGO catalysts.These findings suggest that the PdCuCo/RGO catalyst possesses a great potential as a promising anode catalyst for direct methanol fuel cells.展开更多
We present a straightforward physical approach for synthesizing multiwalled carbon nanotubes(CNTs)-Pd Au/Pt trimetallic nanoparticles(NPs), which allows predesign and control of the metal compositional ratio by simply...We present a straightforward physical approach for synthesizing multiwalled carbon nanotubes(CNTs)-Pd Au/Pt trimetallic nanoparticles(NPs), which allows predesign and control of the metal compositional ratio by simply adjusting the sputtering targets and conditions. The small-sized CNTs-Pd Au/Pt NPs(~3 nm, Pd/Au/Pt ratio of 3:1:2) act as nanocatalysts for the methanol oxidationreaction(MOR), showing excellent performance with electrocatalytic peak current of 4.4 A mg^(-1) Pt and high stability over 7000 s. The electrocatalytic activity and stability of the Pd Au/Pt trimetallic NPs are much superior to those of the corresponding Pd/Pt and Au/Pt bimetallic NPs,as well as a commercial Pt/C catalyst. Systematic investigation of the microscopic, crystalline, and electronic structure of the Pd Au/Pt NPs reveals alloying and charge redistribution in the Pd Au/Pt NPs, which are responsible for the promotion of the electrocatalytic performance.展开更多
A hydrogen evolution-assisted one-pot aqueous approach was developed for facile synthesis of trimetallic Pd Ni Ru alloy nanochain-like networks(Pd Ni Ru NCNs) by only using KBHas the reductant, without any specific ...A hydrogen evolution-assisted one-pot aqueous approach was developed for facile synthesis of trimetallic Pd Ni Ru alloy nanochain-like networks(Pd Ni Ru NCNs) by only using KBHas the reductant, without any specific additive(e.g. surfactant, polymer, template or seed). The products were mainly investigated by transmission electron microscopy(TEM), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS). The hierarchical architectures were formed by the oriented assembly growth and the diffusioncontrolled deposition in the presence of many in-situ generated hydrogen bubbles. The architectures had the largest electrochemically active surface area(ECSA) of 84.32 mgPdthan Pd Ni nanoparticles(NPs,65.23 mgPd), Pd Ru NPs(23.12 mgPd), Ni Ru NPs(nearly zero), and commercial Pd black(6.01 mgPd), outperforming the referenced catalysts regarding the catalytic characters for hydrazine oxygen reaction(HOR). The synthetic route provides new insight into the preparation of other trimetallic nanocatalysts in fuel cells.展开更多
The advancement and growth of nanotechnology lead to realizing new and novel multi-metallic nanostructures with well-defined sizes and morphology,resulting in an improvement in their performance in various catalytic a...The advancement and growth of nanotechnology lead to realizing new and novel multi-metallic nanostructures with well-defined sizes and morphology,resulting in an improvement in their performance in various catalytic applications.The trimetallic nanostructured materials are synthesized and designed in different architectures for energy conversion electrocatalysis.The as-synthesized trimetallic nanostructures have found unique physiochemical properties due to the synergistic combination of the three different metals in their structures.A vast array of approaches such as hydrothermal,solvothermal,seedgrowth,galvanic replacement reaction,biological,and other methods are employed to synthesize the trimetallic nanostructures.Noteworthy,the trimetallic nanostructures showed better performance and durability in the electrocatalytic fuel cells.In the present review,we provide a comprehensive overview of the recent strategies employed for synthesizing trimetallic nanostructures and their energy-related applications.With a particular focus on hydrogen evolution,alcohol oxidations,oxygen evolution,and others,we highlight the latest achievements in the field.展开更多
Metal-organic frameworks(MOFs)can serve as prevailing anodes for lithium-ion batteries,due to their multiple redox-active sites and prominent structural compatibility.However,the poor electronic conductivity and infer...Metal-organic frameworks(MOFs)can serve as prevailing anodes for lithium-ion batteries,due to their multiple redox-active sites and prominent structural compatibility.However,the poor electronic conductivity and inferior cyclability hinder their further implementation.Herein,a synthetic methodology for trimetallic Fe-Co-Ni MOFs with nanoframe superstructures architecture(Fe-Co-Ni NFSs)via structural evolution is proposed for versatile anode materials for lithium storage.Ascribed to optimal compositional and structural optimization,the Fe-Co-Ni NFSs achieve exceptional electrochemical performance with superior specific capacity(1030 mAh g^(−1) at 0.1 A g^(−1)),outstanding rate capacity(414 mAh g^(−1) at 2 A g^(−1)),and prolonged cyclability(489 mAh g^(−1) upon 1000 cycles at 1 A g^(−1)).Both experimental and theoretical investigations reveal that the multi-component metal centers could boost electronic conductivity,confer multiple active sites,and energetically favor Li adsorption capability.Additionally,the nanoframe superstructures of Fe-Co-Ni NFSs could facilitate stress-buffering effect on volumetric expansion and prevent electrode pulverization,further improving the lithium storage capability.This work envisions a meticulous protocol for high-performance MOF anode materials for lithium-ion batteries.展开更多
Although nanostructures based on noble metal alloys are widely utilized in (electro)catalysis, their low-temperature synthesis remains an enormous challenge due to the different Nernst equilibrium potentials of meta...Although nanostructures based on noble metal alloys are widely utilized in (electro)catalysis, their low-temperature synthesis remains an enormous challenge due to the different Nernst equilibrium potentials of metal precursors. Herein, we describe the successful synthesis of trimetallic PtRhNi alloy nanoassemblies (PtRhNi-ANAs) with tunable Pt/Rh ratios using a simple mixed cyanogel reduction method and provide a detailed characterization of their chemical composition, morphology, and structure. Additionally, the electrochemical properties of PtRhNi-ANAs are examined by cyclic voltammetry, revealing composition- dependent electrocatalytic activity in the ethanol oxidation reaction (EOR). Compared to a commercial Pt black electrocatalyst, optimized Pt3Rh1Ni2-ANAs display remarkably enhanced EOR electrocatalytic performance in alkaline media.展开更多
Multimetallic Pt-based alloys with excavated structures have attracted great interest owing to their compositional and morphological tunability, high specific surface areas, and impressive electro-catalytic activities...Multimetallic Pt-based alloys with excavated structures have attracted great interest owing to their compositional and morphological tunability, high specific surface areas, and impressive electro-catalytic activities. Herein, we report the first facile one-pot synthesis of trimetallic Pt-Ni-Cu highly excavated rhombic dodecahedrons (ERDs) with a yield approaching 100%. More importantly, these highly uniform nanocrystals have three-dimensionally accessible excavated surfaces, where abundant stepped atoms are observed. Benefiting from the highly excavated rhombic dodecahedral structures, electronic and synergistic effects within the trimetallic allo3~ and abundant stepped atoms, the as-prepared trimetallic Pt-Ni-Cu ERDs exhibit an enhanced electro-catalytic performance for the electro-oxidation of methanol compared to commercial Pt/C and bimetallic Pt-Cu ERDs and Pt-Ni-Cu solid rhombic dodecahedrons solid rhombic dodecahedrons (SRDs).展开更多
Pt-(Sn,Re)/HZSM5-HMS catalysts were evaluated for n-heptane isomerization at 200–350 ℃.To characterize the catalyst,X-ray diffraction,X-ray fluorescene,Fourier transform infrared spectroscopy,ultraviolet-visible d...Pt-(Sn,Re)/HZSM5-HMS catalysts were evaluated for n-heptane isomerization at 200–350 ℃.To characterize the catalyst,X-ray diffraction,X-ray fluorescene,Fourier transform infrared spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,temperature-programmed reduction of H2,temperature-programmed desorption of NH3,infrared spectroscopy of adsorbed pyridine,H2 chemisorption,nitrogen adsorption-desorption,scanning electron microscopy and thermogravimetric analysis were performed.Kinetics of n-C7 isomerization were investigated under various hydrogen and n-C7 pressures,and the effects of reaction conditions on catalytic performance were studied.The results showed that bi-and trimetallic catalysts exhibit better performance than monometallic catalysts for this reaction.For example,a maximum i-C7 selectivity( 〉74%) and multibranched isomer selectivity(40%) were observed for Pt-Sn/HZSM5-HMS at 200 ℃.展开更多
The development of highly efficient and stable Pd-based catalysts is crucial to improve their sluggish oxygen reduction reaction(ORR)kinetics in acid media.To improve ORR activity and utilization efficiency of Pd,an i...The development of highly efficient and stable Pd-based catalysts is crucial to improve their sluggish oxygen reduction reaction(ORR)kinetics in acid media.To improve ORR activity and utilization efficiency of Pd,an ideal catalyst should have ORR-favorable chemical environment,optimized geometric structure,and long periods of operation.In this work,we first synthesize a novel trimetallic Au@PdPb core–shell catalyst consisting of PdPb alloy nano-layers grown on the surface of ultrathin Au nanowires(NWs)by a two-step water-bath method.The Au@PdPb NWs have the merits of anisotropic one-dimensional nanostructure,high utilization efficiency of Pd atoms and doping of Pb atoms.Because of the structural and multiple compositional advantages,Au@PdPb NWs exhibit remarkably enhanced ORR activity with a high haIf-wave potential(0.827 V),much better than those of commercial Pd black(0.788 V)and bimetallic Au@Pd NWs(0.803 V).Moreover,Au@PdPb NWs display better electrocatalytic stability for the ORR than those of Pd black and Au@Pd NWs.This study demonstrates the validity of our approach for deriving highly ORR-active Pd-based catalysts by modifying their structure and composition.展开更多
The electrocatalytic methanol conversion is of importance in direct methanol fuel cell,biomass reform-ing,and hydrogen generation.To achieve a“carbon-neutral”target,CO_(2)byproducts derived from biofuels should be m...The electrocatalytic methanol conversion is of importance in direct methanol fuel cell,biomass reform-ing,and hydrogen generation.To achieve a“carbon-neutral”target,CO_(2)byproducts derived from biofuels should be mitigated.In contrast to the complete oxidation of methanol to CO_(2),the selective oxidation of methanol to formate is a CO_(2)-emission-free route without the generation of toxic CO intermediates.Herein,we present a highly active catalyst based on transition-metal disulfide nanosheet arrays sup-ported on Ni foam for methanol conversion.Through composition screening,we find that the FeCoNi disulfide nanosheet exhibits a highly efficient and selective methanol-to-formate conversion.The surface reconstruction of this catalyst allows us to produce 0.66 mmol cm^(−2)h^(−1)of formate at low potential(1.40 V)with high faradaic efficiency of>98%.This work offers a substantial composition tuning strat-egy to construct noble-metal-free active multi-metal sites for CO_(2)-emission-free conversion of methanol to value-added formate.展开更多
Water electrolysis is one of the most promising approaches for producing hydrogen.However,it has been hindered by the sluggishness of the anodic oxygen evolution reaction.In this work,we fabricated Ru-Co-Mn trimetalli...Water electrolysis is one of the most promising approaches for producing hydrogen.However,it has been hindered by the sluggishness of the anodic oxygen evolution reaction.In this work,we fabricated Ru-Co-Mn trimetallic alloy nanoparticles on N-doped carbon support(RuCoMn@NC)via the pyrolysis-adsorption-pyrolysis process using ZIF-67 as a precursor.The RuCoMn@NC catalyst exhibited excellent electrocatalytic performance for the hydrogen evolution reaction(HER)over a wide range of pH and glucose oxidation reaction in alkaline media.It showed exceptional HER activity in alkaline medium,superior to that of the commercial Pt/C catalyst(20 wt%),and good electrochemical stability.Further,a two-electrode alkaline electrolyzer pairing RuCoMn@NC as both cathode and anode was employed,and only a cell voltage of 1.63 V was required to attain a current density of 10 mA cm^(-2)in glucose electrolysis,which is about 270 mV lower than that in the overall water-splitting electrolyzer.This paper provides a promising method for developing efficiently bifunctional electrocatalysts driving redox electrocatalysis,and it would be beneficial to energy-saving electrolytic H_(2) production.展开更多
Mesocrystals, the non-classical crystals with highly ordered nanoparticle superstructures, have shown great potential in many applications because of their newly collective properties. However, there is still a lack o...Mesocrystals, the non-classical crystals with highly ordered nanoparticle superstructures, have shown great potential in many applications because of their newly collective properties. However, there is still a lack of a facile and general synthesis strategy to organize and integrate distinct components into complex mesocrystals, and of reported application for them in industrial catalytic reactions. Herein we report a general bottom-up synthesis of CuO-based trimetallic oxide mesocrystals (denoted as CuO-M1Ox-M2Oy, where M1 and M2 = Zn, In, Fe, Ni, Mn, and Co) using a simple precipitation method followed by a hydrothermal treatment and a topotactic transformation via calcination. When these mesocrystals were used as the catalyst to produce trichlorosilane (TCS) via Si hydrochlorination reaction, they exhibited excellent catalytic performance with much increased Si conversion and TCS selectivity. In particular, the TCS yield was increased 19-fold than that of the catalyst-free process. The latter is the current industrial process. The efficiently catalytic property of these mesocrystals is attributed to the formation of well-defined nanoscale heterointerfaces that can effectively facilitate the charge transfer, and the generation of the compressive and tensile strain on CuO near the interfaces among different metal oxides. The synthetic approach developed here could be applicable to fabricate versatile complicated metal oxide mesocrystals as novel catalysts for various industrial chemical reactions.展开更多
The present paper covers the reaction of sodium tricarbonyl cyclopentadienyl or substituted cyclopentadienyl tungsten with triphenyl(tribenzyl) tin chloride or diphenyl(dibenzyl) tin dichloride to yield bimetallic com...The present paper covers the reaction of sodium tricarbonyl cyclopentadienyl or substituted cyclopentadienyl tungsten with triphenyl(tribenzyl) tin chloride or diphenyl(dibenzyl) tin dichloride to yield bimetallic complexes R 3SnW(CO) 3Cp * or trimetallic complexes R 2Sn[W(CO) 3Cp *] 2(R=Ph, PhCH 2; Cp *=C 5H 5, CH 3C 5H 4, CH 3COC 5H 4, 1,2,4 Ph 3C 5H 2). They were characterized by means of elemental analysis, IR and 1H NMR. The crystal of Ph 3SnW(CO) 3C 5H 4CH 3 is orthorhombic, space group is P bca with a =1 146 5(2) nm, b =1 674 7(6) nm, c =2 496(1) nm, Z =8 and Sn—W bond length of 0 283 22 nm.展开更多
Single cluster catalysts(SCCs),which exhibit remarkable catalytic performance due to their high metal loading and synergy effect between metal atoms,have attracted great attention in research.Herein,by means of densit...Single cluster catalysts(SCCs),which exhibit remarkable catalytic performance due to their high metal loading and synergy effect between metal atoms,have attracted great attention in research.Herein,by means of density functional theory calculations,the oxygen reduction reaction(ORR),oxygen evolution reaction(OER),hydrogen evolution reaction(HER)performances of precious metal(Pt,Pd,Rh,Ir)trimetallic single-cluster electrocatalyst(U_(x)V_(y)W_(z)-NG)are investigated.The calculation results show that Pt,Pd,Ir have significant effect on ORR,OER,HER,respectively,all the calculated U_(x)V_(y)W_(z)-NG structures are thermodynamically stable due to the negative formation energies and binding energies.The Pt_(3)-NG,Pd_(3)-NG,Ir_(3)-NG show the lowest ORR,OER,HER overpotentials of 0.63,0.77,−0.02 V,respectively,among all combinations of U_(x)V_(y)W_(z)-NG.These overpotentials are lower than that of precious metal single atom catalysts(SACs),which indicate better activities of precious trimetallic SCCs than those of SACs.The electronic structure reveals that the O-2p orbital shows strong hybridization strength with Pt-3d orbitals in the system of OH adsorbed Pt_(3)-NG and thus facilitates the electrocatalytic reactions.The results are helpful for the rational design of high-performance triatomic catalysts.展开更多
基金supported by the Natural Science Foundation of China (Nos.21776302,21576289,and 21776308)the Science Foundation of China University of Petroleum,Beijing (Nos.2462017BJB04,2462015YQ0306,2462016YJRC027 and C201603)
文摘Trimetallic palladium-copper-cobalt nanoparticles supported on reduced graphene oxide(PdCuCo/RGO)with different molar ratios of Pd,Cu and Co can be synthesized by facile chemical reduction with NaBH_4 as reductant and cetrimonium bromide as stabilizer.The morphology,structure and composition of the as-synthesized catalysts are characterized by transmission electron microscopy,X-ray diffraction and Xray photoelectron spectroscopy.The cyclic voltammetry and chronoamperometry are utilized to investigate the electrochemical activities and stabilities of the as-obtained catalysts.The results demonstrate that the PdCuCo/RGO catalyst shows superior catalytic activity and stability for methanol electrooxidation in alkaline media compared with PdCu/RGO,PdCo/RGO,and Pd/RGO catalysts.These findings suggest that the PdCuCo/RGO catalyst possesses a great potential as a promising anode catalyst for direct methanol fuel cells.
基金supported by the National Natural Science Foundation of China (Nos. 61675143, 11661131002)the Natural Science Foundation of Jiangsu Province (No. BK20160277)+2 种基金the Soochow University-Western University Joint Centre for Synchrotron Radiation Researchthe Collaborative Innovation Center of Suzhou Nano Science & Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘We present a straightforward physical approach for synthesizing multiwalled carbon nanotubes(CNTs)-Pd Au/Pt trimetallic nanoparticles(NPs), which allows predesign and control of the metal compositional ratio by simply adjusting the sputtering targets and conditions. The small-sized CNTs-Pd Au/Pt NPs(~3 nm, Pd/Au/Pt ratio of 3:1:2) act as nanocatalysts for the methanol oxidationreaction(MOR), showing excellent performance with electrocatalytic peak current of 4.4 A mg^(-1) Pt and high stability over 7000 s. The electrocatalytic activity and stability of the Pd Au/Pt trimetallic NPs are much superior to those of the corresponding Pd/Pt and Au/Pt bimetallic NPs,as well as a commercial Pt/C catalyst. Systematic investigation of the microscopic, crystalline, and electronic structure of the Pd Au/Pt NPs reveals alloying and charge redistribution in the Pd Au/Pt NPs, which are responsible for the promotion of the electrocatalytic performance.
基金financially supported by the Nation Natural Science Foundation of China(No.21475118)
文摘A hydrogen evolution-assisted one-pot aqueous approach was developed for facile synthesis of trimetallic Pd Ni Ru alloy nanochain-like networks(Pd Ni Ru NCNs) by only using KBHas the reductant, without any specific additive(e.g. surfactant, polymer, template or seed). The products were mainly investigated by transmission electron microscopy(TEM), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS). The hierarchical architectures were formed by the oriented assembly growth and the diffusioncontrolled deposition in the presence of many in-situ generated hydrogen bubbles. The architectures had the largest electrochemically active surface area(ECSA) of 84.32 mgPdthan Pd Ni nanoparticles(NPs,65.23 mgPd), Pd Ru NPs(23.12 mgPd), Ni Ru NPs(nearly zero), and commercial Pd black(6.01 mgPd), outperforming the referenced catalysts regarding the catalytic characters for hydrazine oxygen reaction(HOR). The synthetic route provides new insight into the preparation of other trimetallic nanocatalysts in fuel cells.
文摘The advancement and growth of nanotechnology lead to realizing new and novel multi-metallic nanostructures with well-defined sizes and morphology,resulting in an improvement in their performance in various catalytic applications.The trimetallic nanostructured materials are synthesized and designed in different architectures for energy conversion electrocatalysis.The as-synthesized trimetallic nanostructures have found unique physiochemical properties due to the synergistic combination of the three different metals in their structures.A vast array of approaches such as hydrothermal,solvothermal,seedgrowth,galvanic replacement reaction,biological,and other methods are employed to synthesize the trimetallic nanostructures.Noteworthy,the trimetallic nanostructures showed better performance and durability in the electrocatalytic fuel cells.In the present review,we provide a comprehensive overview of the recent strategies employed for synthesizing trimetallic nanostructures and their energy-related applications.With a particular focus on hydrogen evolution,alcohol oxidations,oxygen evolution,and others,we highlight the latest achievements in the field.
基金We gratefully acknowledge the financial support from the Guangzhou Science and Technology Project (No.201904010213).
文摘Metal-organic frameworks(MOFs)can serve as prevailing anodes for lithium-ion batteries,due to their multiple redox-active sites and prominent structural compatibility.However,the poor electronic conductivity and inferior cyclability hinder their further implementation.Herein,a synthetic methodology for trimetallic Fe-Co-Ni MOFs with nanoframe superstructures architecture(Fe-Co-Ni NFSs)via structural evolution is proposed for versatile anode materials for lithium storage.Ascribed to optimal compositional and structural optimization,the Fe-Co-Ni NFSs achieve exceptional electrochemical performance with superior specific capacity(1030 mAh g^(−1) at 0.1 A g^(−1)),outstanding rate capacity(414 mAh g^(−1) at 2 A g^(−1)),and prolonged cyclability(489 mAh g^(−1) upon 1000 cycles at 1 A g^(−1)).Both experimental and theoretical investigations reveal that the multi-component metal centers could boost electronic conductivity,confer multiple active sites,and energetically favor Li adsorption capability.Additionally,the nanoframe superstructures of Fe-Co-Ni NFSs could facilitate stress-buffering effect on volumetric expansion and prevent electrode pulverization,further improving the lithium storage capability.This work envisions a meticulous protocol for high-performance MOF anode materials for lithium-ion batteries.
基金Acknowledgements We acknowledge financial support by the National Natural Science Foundation of China (Nos. 21473111 and 21376122), Fundamental Research Funds for the Central Universities (No. GK201602002), Innovation Foundation of Shenzhen Government (No. JCYJ20160408173202143), the Joint Fund of Energy Storage of Qingdao (No. 20160012), and the Fundamental Research Funds of Huazhong University of Science and Technology (Nos. 3004013109 and 0118013089). We acknowledge the support of Analytical and Testing Center of Huazhong University of Science and Technology for SEM and XPS measurements.
文摘Although nanostructures based on noble metal alloys are widely utilized in (electro)catalysis, their low-temperature synthesis remains an enormous challenge due to the different Nernst equilibrium potentials of metal precursors. Herein, we describe the successful synthesis of trimetallic PtRhNi alloy nanoassemblies (PtRhNi-ANAs) with tunable Pt/Rh ratios using a simple mixed cyanogel reduction method and provide a detailed characterization of their chemical composition, morphology, and structure. Additionally, the electrochemical properties of PtRhNi-ANAs are examined by cyclic voltammetry, revealing composition- dependent electrocatalytic activity in the ethanol oxidation reaction (EOR). Compared to a commercial Pt black electrocatalyst, optimized Pt3Rh1Ni2-ANAs display remarkably enhanced EOR electrocatalytic performance in alkaline media.
文摘Multimetallic Pt-based alloys with excavated structures have attracted great interest owing to their compositional and morphological tunability, high specific surface areas, and impressive electro-catalytic activities. Herein, we report the first facile one-pot synthesis of trimetallic Pt-Ni-Cu highly excavated rhombic dodecahedrons (ERDs) with a yield approaching 100%. More importantly, these highly uniform nanocrystals have three-dimensionally accessible excavated surfaces, where abundant stepped atoms are observed. Benefiting from the highly excavated rhombic dodecahedral structures, electronic and synergistic effects within the trimetallic allo3~ and abundant stepped atoms, the as-prepared trimetallic Pt-Ni-Cu ERDs exhibit an enhanced electro-catalytic performance for the electro-oxidation of methanol compared to commercial Pt/C and bimetallic Pt-Cu ERDs and Pt-Ni-Cu solid rhombic dodecahedrons solid rhombic dodecahedrons (SRDs).
文摘Pt-(Sn,Re)/HZSM5-HMS catalysts were evaluated for n-heptane isomerization at 200–350 ℃.To characterize the catalyst,X-ray diffraction,X-ray fluorescene,Fourier transform infrared spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,temperature-programmed reduction of H2,temperature-programmed desorption of NH3,infrared spectroscopy of adsorbed pyridine,H2 chemisorption,nitrogen adsorption-desorption,scanning electron microscopy and thermogravimetric analysis were performed.Kinetics of n-C7 isomerization were investigated under various hydrogen and n-C7 pressures,and the effects of reaction conditions on catalytic performance were studied.The results showed that bi-and trimetallic catalysts exhibit better performance than monometallic catalysts for this reaction.For example,a maximum i-C7 selectivity( 〉74%) and multibranched isomer selectivity(40%) were observed for Pt-Sn/HZSM5-HMS at 200 ℃.
基金supported by the Academic Research Fund(AcRF)Tier 1 Grant(No.RG105/19)from the Ministry of Education in Singapore,the National Natural Science Foundation of China(No.21875112)and the China Scholarship Council(No.201906090199).
文摘The development of highly efficient and stable Pd-based catalysts is crucial to improve their sluggish oxygen reduction reaction(ORR)kinetics in acid media.To improve ORR activity and utilization efficiency of Pd,an ideal catalyst should have ORR-favorable chemical environment,optimized geometric structure,and long periods of operation.In this work,we first synthesize a novel trimetallic Au@PdPb core–shell catalyst consisting of PdPb alloy nano-layers grown on the surface of ultrathin Au nanowires(NWs)by a two-step water-bath method.The Au@PdPb NWs have the merits of anisotropic one-dimensional nanostructure,high utilization efficiency of Pd atoms and doping of Pb atoms.Because of the structural and multiple compositional advantages,Au@PdPb NWs exhibit remarkably enhanced ORR activity with a high haIf-wave potential(0.827 V),much better than those of commercial Pd black(0.788 V)and bimetallic Au@Pd NWs(0.803 V).Moreover,Au@PdPb NWs display better electrocatalytic stability for the ORR than those of Pd black and Au@Pd NWs.This study demonstrates the validity of our approach for deriving highly ORR-active Pd-based catalysts by modifying their structure and composition.
基金support from the Recruitment Program of Thousand Youth Talentssupport from the program of China Scholarships Council (No.202006070158)+1 种基金International Postdoctoral Exchange Fellowship Program (Talent-Introduction Program,No.YJ20190126) in 2019the project (No.2019M663468) funded by the China Postdoctoral Science Foundation。
文摘The electrocatalytic methanol conversion is of importance in direct methanol fuel cell,biomass reform-ing,and hydrogen generation.To achieve a“carbon-neutral”target,CO_(2)byproducts derived from biofuels should be mitigated.In contrast to the complete oxidation of methanol to CO_(2),the selective oxidation of methanol to formate is a CO_(2)-emission-free route without the generation of toxic CO intermediates.Herein,we present a highly active catalyst based on transition-metal disulfide nanosheet arrays sup-ported on Ni foam for methanol conversion.Through composition screening,we find that the FeCoNi disulfide nanosheet exhibits a highly efficient and selective methanol-to-formate conversion.The surface reconstruction of this catalyst allows us to produce 0.66 mmol cm^(−2)h^(−1)of formate at low potential(1.40 V)with high faradaic efficiency of>98%.This work offers a substantial composition tuning strat-egy to construct noble-metal-free active multi-metal sites for CO_(2)-emission-free conversion of methanol to value-added formate.
基金supported by the National Natural Science Foundation of China(52072035,51631001,21801015,51902023 and 51872030)the Fundamental Research Funds for the Central Universities(2017CX01003)+1 种基金Beijing Institute of Technology Research Fund Program for Young Scholarsthe Joint R&D Plan of Hong Kong,Macao,Taiwan,and Beijing(Z191100001619002).
文摘Water electrolysis is one of the most promising approaches for producing hydrogen.However,it has been hindered by the sluggishness of the anodic oxygen evolution reaction.In this work,we fabricated Ru-Co-Mn trimetallic alloy nanoparticles on N-doped carbon support(RuCoMn@NC)via the pyrolysis-adsorption-pyrolysis process using ZIF-67 as a precursor.The RuCoMn@NC catalyst exhibited excellent electrocatalytic performance for the hydrogen evolution reaction(HER)over a wide range of pH and glucose oxidation reaction in alkaline media.It showed exceptional HER activity in alkaline medium,superior to that of the commercial Pt/C catalyst(20 wt%),and good electrochemical stability.Further,a two-electrode alkaline electrolyzer pairing RuCoMn@NC as both cathode and anode was employed,and only a cell voltage of 1.63 V was required to attain a current density of 10 mA cm^(-2)in glucose electrolysis,which is about 270 mV lower than that in the overall water-splitting electrolyzer.This paper provides a promising method for developing efficiently bifunctional electrocatalysts driving redox electrocatalysis,and it would be beneficial to energy-saving electrolytic H_(2) production.
基金the National Natural Science Foundation of China(Nos.21878301,21978299,and 21908224)Z.Z.thanks the kind support of Guangdong Technion Israel Institute of Technology(GTTIT)for the collaboration.
文摘Mesocrystals, the non-classical crystals with highly ordered nanoparticle superstructures, have shown great potential in many applications because of their newly collective properties. However, there is still a lack of a facile and general synthesis strategy to organize and integrate distinct components into complex mesocrystals, and of reported application for them in industrial catalytic reactions. Herein we report a general bottom-up synthesis of CuO-based trimetallic oxide mesocrystals (denoted as CuO-M1Ox-M2Oy, where M1 and M2 = Zn, In, Fe, Ni, Mn, and Co) using a simple precipitation method followed by a hydrothermal treatment and a topotactic transformation via calcination. When these mesocrystals were used as the catalyst to produce trichlorosilane (TCS) via Si hydrochlorination reaction, they exhibited excellent catalytic performance with much increased Si conversion and TCS selectivity. In particular, the TCS yield was increased 19-fold than that of the catalyst-free process. The latter is the current industrial process. The efficiently catalytic property of these mesocrystals is attributed to the formation of well-defined nanoscale heterointerfaces that can effectively facilitate the charge transfer, and the generation of the compressive and tensile strain on CuO near the interfaces among different metal oxides. The synthetic approach developed here could be applicable to fabricate versatile complicated metal oxide mesocrystals as novel catalysts for various industrial chemical reactions.
文摘The present paper covers the reaction of sodium tricarbonyl cyclopentadienyl or substituted cyclopentadienyl tungsten with triphenyl(tribenzyl) tin chloride or diphenyl(dibenzyl) tin dichloride to yield bimetallic complexes R 3SnW(CO) 3Cp * or trimetallic complexes R 2Sn[W(CO) 3Cp *] 2(R=Ph, PhCH 2; Cp *=C 5H 5, CH 3C 5H 4, CH 3COC 5H 4, 1,2,4 Ph 3C 5H 2). They were characterized by means of elemental analysis, IR and 1H NMR. The crystal of Ph 3SnW(CO) 3C 5H 4CH 3 is orthorhombic, space group is P bca with a =1 146 5(2) nm, b =1 674 7(6) nm, c =2 496(1) nm, Z =8 and Sn—W bond length of 0 283 22 nm.
基金the 2022 Youth Scientific Research Fund Project of Qinghai University(No.2022-QGY-2)Qinghai Provincial Key Laboratory of New Light Alloys(No.2022-ZJY20)Kunlun Talent Project Program of Qinghai Province.
文摘Single cluster catalysts(SCCs),which exhibit remarkable catalytic performance due to their high metal loading and synergy effect between metal atoms,have attracted great attention in research.Herein,by means of density functional theory calculations,the oxygen reduction reaction(ORR),oxygen evolution reaction(OER),hydrogen evolution reaction(HER)performances of precious metal(Pt,Pd,Rh,Ir)trimetallic single-cluster electrocatalyst(U_(x)V_(y)W_(z)-NG)are investigated.The calculation results show that Pt,Pd,Ir have significant effect on ORR,OER,HER,respectively,all the calculated U_(x)V_(y)W_(z)-NG structures are thermodynamically stable due to the negative formation energies and binding energies.The Pt_(3)-NG,Pd_(3)-NG,Ir_(3)-NG show the lowest ORR,OER,HER overpotentials of 0.63,0.77,−0.02 V,respectively,among all combinations of U_(x)V_(y)W_(z)-NG.These overpotentials are lower than that of precious metal single atom catalysts(SACs),which indicate better activities of precious trimetallic SCCs than those of SACs.The electronic structure reveals that the O-2p orbital shows strong hybridization strength with Pt-3d orbitals in the system of OH adsorbed Pt_(3)-NG and thus facilitates the electrocatalytic reactions.The results are helpful for the rational design of high-performance triatomic catalysts.