Catalytic effect in lithium metal batteries: From heterogeneous catalyst to homogenous catalyst

Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical capacity.Toward the broader implementation,the primary obstacle lies in the intricate multi-electron,multi-step redox reaction associated with sluggish conversion kinetics,subsequently giving rise to a cascade of parasitic issues.In order to smooth reaction kinetics,catalysts are widely introduced to accelerate reaction rate via modulating the energy barrier.Over past decades,a large amount of research has been devoted to the catalyst design and catalytic mechanism exploration,and thus the great progress in electrochemical performance has been realized.Therefore,it is necessary to make a comprehensive review toward key progress in catalyst design and future development pathway.In this review,the basic mechanism of lithium metal batteries is provided along with corresponding advantages and existing challenges detailly described.The main catalysts employed to accelerate cathode reaction with emphasis on their catalytic mechanism are summarized as well.Finally,the rational design and innovative direction toward efficient catalysts are suggested for future application in metal-sulfur/gas battery and beyond.This review is expected to drive and benefit future research on rational catalyst design with multi-parameter synergistic impacts on the activity and stability of next-generation metal battery,thus opening new avenue for sustainable solution to climate change,energy and environmental issues,and the potential industrial economy.

Silica supported perchloric acid(HClO_4-SiO_2):A mild,reusable and highly efficient heterogeneous catalyst for the synthesis of amidoalkyl naphthols

An efficient and direct procedure has been developed for the preparation of amidoalkyl naphthols by a one-pot condensation of aryl aldehydes, 2-naphthol and urea or amides, in the presence of HClO4-SiO2 as a heterogeneous catalyst. The reactions were carried out under reflux and solvent-free conditions. The present methodology offers several advantages such as excellent yields, simple procedure, easy work-up and ecofriendly reaction condition. The catalyst is easily prepared, stable, reusable and efficient under the reaction conditions.

Salen-Cu(Ⅱ)@MIL-101(Cr)as an efficient heterogeneous catalyst for cycloaddition of CO2 to epoxides under mild conditions

A double active center system, namely Salen-Cu（Ⅱ）@MIL-101（Cr）, was successfully synthesized via the"ship in a bottle" approach, which acted as a bifunctional material for both capture and conversion of COin a single process. For the first time, Salen-Cu（Ⅱ）@MIL-101（Cr） catalyst was developed for the synthesis of propylene carbonate from COand propylene oxide under room temperature and ambient pressure with a yield of 87.8% over 60 h. Furthermore, the reaction mechanism was also discussed.

Solar-Driven Hydrogen Peroxide Production Using Polymer-Supported Carbon Dots as Heterogeneous Catalyst

Safe, sustainable, and green production of hydro gen peroxide is an exciting proposition due to the role of hydrogen peroxide as a green oxidant and energy carrier for fuel cells. The current work reports the development of carbon dot-impregnated waterborne hyperbranched polyurethane as a heterogeneous photo-catalyst for solar-driven production of hydrogen peroxide. The results reveal that the carbon dots possess a suitable band-gap of 2.98 eV,which facilitates effective splitting of both water and ethanol under solar irradiation. Inclusion of the carbon dots within the eco-friendly polymeric material ensures their catalytic activity and also provides a facile route for easy catalyst separation, especially from a solubilizing medium.The overall process was performed in accordance with the principles of green chemistry using bio-based precursorsand aqueous medium. This work highlights the potential of carbon dots as an effective photo-catalyst.

Silica supported ammonium dihydrogen phosphate(NH_4H_2PO_4/SiO_2):A mild,reusable and highly efficient heterogeneous catalyst for the synthesis of 14-aryl-14-H-dibenzo[a,j]xanthenes

catalyst for the synthesis of 14-aryl- 14-H-dibenzo[aj]xanthenes Silica supported ammonium dihydrogen phosphate （NH4H2PO4/SiO2） is found to be a recyclable heterogeneous catalyst for a rapid and efficient synthesis of various aryl-14-H-dibenzo[a,j]xanthenes with excellent yields under solvent-free conditions. The present methodology offers several advantages such as excellent yields, simple procedure, short reaction times and milder conditions. 2009 Shahnaz Rostamizadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Co-salen functionalized on graphene as an efficient heterogeneous catalyst for cyclohexene oxidation

Co-salen functionalized on graphene with an average pore size of 27.7 nm as a heterogeneous catalyst exhibited good catalytic activity and recyclability in cyclohexene oxidation.

ZnO-beta zeolite:As an effective and eco-friendly heterogeneous catalyst for the synthesis of benzothiazole derivatives

A cheap and recyclable ZnO-beta zeolite was used as catalyst for the synthesis of benzothiazole derivatives.This method provides several advantages such as environmental friendliness,short reaction times,high yields,simple work-up procedure and catalyst was successfully reused for four cycles without significant loss of activity.

Novel HBD-Containing Zn (dobdc) (datz) as efficiently heterogeneous catalyst for CO_(2) chemical conversion under mild conditions

A novel Zn-based metal–organic framework Zn(dobdc)(datz)[Zn_(2)(H2dobdc)(datz)2$1.5DMF]with plentiful hydrogen bond donors(HBD)groups was facilely synthesized from mixed ligands.The dual activation of metal Zn sites and HBD groups for epoxides by forming Zn–O adduct and hydrogen bonds facilitated the ring-opening of epoxide substrate,which is critical for the subsequent CO_(2) fixation.Also,the existence of micropores and N-rich units in Zn(dobdc)(datz)afforded affinity towards CO_(2),which is beneficial to further improvement on catalytic CO_(2) conversion performance.Satisfactorily,Zn(dobdc)(datz)/Bu4NBr system was proved efficient heterogeneous catalyst for the CO_(2) cycloaddition with epoxides,and 98%propylene carbonate yield was obtained under mild conditions(80C,1.5 MPa and solvent-free).In addition,Zn(dobdc)(datz)/Bu4NBr exhibited remarkable versatility to different epoxides and could be completely recycled over six runs with high catalytic activity.The highly stable,easily recycle and solvent-free Zn-based MOF reported here displays eco-friendly and efficient performance to CO_(2)conversion.

Cobalt-based heterogeneous catalysts for photocatalytic carbon dioxide reduction

Solar light-driven CO_(2)reduction to high value-added chemicals has considered as an outstanding way to solve energy crisis and climate warming.Recently,various photocatalysts have been developed to achieve this reaction.Among them,cobaltbased heterogeneous catalysts have attracted great interest because of their promising performance,product selectivity and stability.Herein,we systematically summarize the research progress of various cobalt-based heterogeneous catalysts for the photoreduction of CO_(2),such as single-atom cobalt,and cobalt-based oxides,nitrides,sulfi des,phosphides,metal-organic frameworks and covalent-organic frameworks.Meanwhile,the advantages and structure-activity relationship of these catalysts in photocatalytic CO_(2)reduction reaction are discussed.Finally,the challenges and prospects for constructing cobaltbased heterogeneous catalysts with high effi ciency are highlighted.

Four unprecedented V_(14)clusters as highly efficient heterogeneous catalyst for CO_(2)fixation with epoxides and oxidation of sulfides

Chemical fixation of carbon dioxide(CO_(2))is an energy-saving method for alleviating the greenhouse gas emissions,whereas it persists a challenge posed by the demand for efficient catalysts.Herein,four unprecedented examples of tetradecanuclear vanadium clusters,namely,[(C_(2)H_(8)N_(2))6(CH_(3)O)8(CH_(3)OH)_(2)V_(10)^(Ⅳ)V_(4)ⅤO_(26)](V_(14)-1),[(C_(3)H_(10)N_(2))_(6)(CH_(3)O)_(8)(CH_(3)OH)_(2)V_(10)^(Ⅳ)V_(4)ⅤO_(26)](V14^(-2)),[(C_(6)H_(14)N_(2))6(CH_(3)O)8(CH_(3)OH)_(2)V_(10)^(Ⅳ)V_(4)ⅤO_(26)]·5H_(2)O(V14^(-3))and[(C_(4)H_(12)N_(2)O)_(4)(C_(4)H_(11)N_(2)O)_(2)(CH_(3)O)_(2)V_(10)^(Ⅳ)V_(4)ⅤO_(28)]·6H_(2)O(V_(14)-4),have been triumphantly designed and constructed under solvothermal conditions.Among them,compounds V_(14)-1–4 are the first cases of tetradecanuclear vanadium clusters without the introduction of inorganic acid radical ions.Two main units[V_(10)^(Ⅳ)V_(4)ⅤO_(26)]8+and[V10ⅣV4ⅤO28]4+represent brand-new configurations of tetradecanuclear vanadium clusters.Given the fact that the presence of V^(Ⅳ)/V^(Ⅴ)can potentially facilitate electron transfer and consequently expedite catalytic reactions,we explored the catalytic activities of these compounds.Remarkably,V_(14)-1 was further used as a heterogeneous catalyst in the CO_(2)fixation into cyclic carbonates under milder conditions(60℃,0.5 MPa)and exhibited higher catalytic activity.Also,the experimental results indicated that V_(14)-1 could efficiently catalyze the sulfoxidation,which could fully convert most sulfides within 40 min at room temperature.Moreover,as a stable heterogeneous catalyst employed in CO_(2)fixation with epoxides and oxidation of sulfides,V_(14)-1 could be consecutively used multiple cycles without losing its catalytic activity.

Enabling heterogeneous catalysis to achieve carbon neutrality: Directional catalytic conversion of CO_(2) into carboxylic acids

The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.

Highly reactive and reusable heterogeneous activated carbons-based palladium catalysts for Suzuki-Miyaura reaction

Suzuki-Miyaura reaction of aryl halides with phenylboronic acid using a heterogeneous palladium catalyst based on activated carbons(AC) was systematically investigated in this work. Two different reaction modes(batch procedure and continuous-flow procedure) were used to study the variations of reaction processing. The heterogeneous catalysts presented excellent reactivity and recyclability for iodobenzene and bromobenzene substrates in batch mode, which can be attributed to stabilization of Pd nanoparticles by the thiol and amino groups on the AC supports. However, significant dehalogenation in the reaction mixture and Pd leaching from the heterogeneous catalysts were observed in continuous-flow mode.This unique phenomenon in continuous-flow mode resulted in a dramatic decline in reaction selectivity and durability of heterogeneous catalysts comparing with that of batch mode. In addition, the heterogeneous Pd catalysts with thiol-and amino-modified AC supports exhibited different reactivity and durability in batch and continuous-flow mode owing to the difference of interaction between Pd species and AC supports.

β-Cyclodextrin Immobilized onto Dowex Resin： A Unique Microvessel and Heterogeneous Catalyst in Nucleophilic Substitution Reactions

The catalytic activity ofβ-cyclodextrin immobilized on Dowex resin as an efficient solid-liquid phase transfer catalyst was developed for the synthesis of alkyl thiocyanates and phenacyl derivatives in water. The nucleophilic substitution reactions were performed under mild reaction condition and gave the products in excellent yields. Fur thermore, the catalyst could be recycled by facile separation without any loss of activity.

Computational design of heterogeneous catalysts and gas separation materials for advanced chemical processing

Functional materials are widely used in chemical industry in order to reduce the process cost while simultaneously increase the product quality.Considering their significant effects,systematic methods for the optimal selection and design of materials are essential.The conventional synthesis-and-test method for materials development is inefficient and costly.Additionally,the performance of the resulting materials is usually limited by the designer’s expertise.During the past few decades,computational methods have been significantly developed and they now become a very important tool for the optimal design of functional materials for various chemical processes.This article selectively focuses on two important process functional materials,namely heterogeneous catalyst and gas separation agent.Theoretical methods and representative works for computational screening and design of these materials are reviewed.

Metal-organic layers as reusable solid fluorination reagents and heterogeneous catalysts for aromatic fluorination

Reusable solid fluorination reagents and heterogeneous catalysts are ideally suited for late-stage fluorination with fast and clean conversion and simplified work-up.Here we report Pd-functionalized two-dimensional metal-organic layers(MOLs)as solid reagents and heterogeneous catalysts to efficiently fluorinate a broad scope of aromatic compounds.Site isolation in the MOLs provides a unique opportunity to stabilize highly active F-containing species for the chemical conversion.A terpyridine(TPY)-based ligand on the MOL,together with a 2-chloro-1,10-phenanthroline(phenCl)as a co-ligand,chelates Pd^(Ⅱ)toform a reactive center.After treatment with Selectfluor/H_(2)0,an(N-fluoroxy)-(2-chloro)-phenanthrolinium[N-(FO)-phenCl^(+)]moiety is produced from the co-ligand on the Pd center.This active species serves as a stochiometric solid fluorination reagent,which shows different regioselectivities and reactivities as compared to homogeneous catalysts that involves Pd^(Ⅲ/Ⅳ)-F intermediates in catalytic cycles.The MOLs can also be used as heterogeneous catalysts for fluorination using Selectfluor.This work highlights opportunities in using MOLs to stabilize unique active sites for late-stage fluorination.

Preparation of Pt/γ-Al2O3-C Heterogeneous Catalyst for Highly Selective Hydrogenation of Cinnamaldehyde Towards Cinnamyl Alcohol

A Pt/γ-Al2O3-C heterogeneous catalyst with improved catalytic performance was successfully prepared. Bayberry talmin（BT）, an abundant natural plant polyphenol, was utilized to modifiy the surface of the Pt/γ-Al2O3 matrix and then stabilize Pt nanoparticles（NPs）. The catalyst was systematically and specifically characterized by a collec- tion of analytic tools including XRD, XPS, FTIR, TEM, and TG. It was found that the Pt NPs were envenly dispered on the γ-Al2O3-C matrix. Meanwhile, when the catalyst was applied for selective hydrogenation of cilmamalde- hyde（CMA） in the presence of KOH promoter in solvent, excellent catalytic performance was obtained. The selecti- vity to cinnamyl alcohol（CMO） reached 97.88% with 88.45% CMA conversion within 30 min in the presence of 0.037 mol/L KOH, without significant loss of catalytic activity even under cyclic measurements for 5 times. The excelleut catalytic performances should be ascribed predominantly to the uniform and stable dispersion ofPt NPs on the γ-Al2O3-C matrix and the excellent heat stability of BT.

Nanoparticles@nanoscale metal-organic framework composites as highly efficient heterogeneous catalysts for size-and shape-selective reactions

Composites incorporating nanoparticles （NPs） within metal-organic frameworks （MOFs） find applications in many different fields.In particular,using MOF layers as molecular sieves built on the NPs could enable selectivity in heterogeneous catalysis.However,such composites typically exhibit low catalytic efficiency,due to the slow diffusion of the reactants in the long and narrow channels of the MOF shell.In order to improve the catalytic efficiency of these systems,here we report the fabrication of NPs incorporated in nanosized MOFs （NPs@nano-MOFs）,obtained by reducing the size of the MOF crystals grown around the NPs.The crystal size of the composites was controlled by modulating the nucleation rate of the MOFs during the encapsulation of pre-synthesized and catalytically active NPs;in this way,NPs@MOF crystals smaller than 50 nm were synthesized and subsequently used as highly efficient catalysts.Due to the shorter path from the MOF surface to the active sites,the obtained Pt@nano-MOFs composites showed a higher conversion rate than their larger-sized counterparts in the synthesis of imines via cascade reaction of nitrobenzene and in the hydrogenation of olefins,while retaining the excellent size and shape selectivity associated with the molecular sieving effect of the MOF layer.The present strategy can also be applied to prepare other encapsulated nanostructures combining various types of NPs and nano-MOFs,thus highlighting the broad potential of this approach for developing optimized catalysts with high reactivity and selectivity.

Fenton-like degradation of Methylene Blue using paper mill sludge-derived magnetically separable heterogeneous catalyst:Characterization and mechanism

For the paper industry, the disposal and management of the yielded sludge are a considerable challenge. In our work, the paper mill sludge-derived magnetically separable heterogeneous catalyst（PMS-Fe-380） was prepared easily through a facile synthesis method. The morphology and structure of PMS-Fe-380 were fully characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer–Emmet–Teller analysis. The catalytic activity of PMS-Fe-380 was evaluated by degradation of Methylene Blue（MB）. The reusability and stability of PMS-Fe-380 were evaluated in five repeated runs, which suggested that PMS-Fe-380 manifested excellent stability of catalytic activity. Moreover,leaching tests indicated that the leached iron is negligible（〈0.5 mg/L）. This study provides an alternative environmentally friendly reuse method for paper mill sludge and a novel catalyst PMS-Fe-380 that can be considered as a promising heterogeneous Fenton-like catalyst.

SnCl_2/nano SiO_2: A green and reusable heterogeneous catalyst for the synthesis of polyfunctionalized 4H-pyrans

A highly efficient and general method for the synthesis of polyfunctionalized 4H-pyrans is established through a one-pot multicomponent cyclocondensation of aromatic aldehydes with CH acids, malononitrile and ethyl acetoacetate using nano silica supported tin （II） chloride as a catalyst. In this method SnCl2/nano Si02 was used as green and reusable catalyst. Excellent yields, short reaction times, simple workup, and inexpensiveness and commercially availability of the catalyst are the advantages of this method.

Photodegradation of Orange Ⅱ using waste paper sludge-derived heterogeneous catalyst in the presence of oxalate under ultraviolet light emitting diode irradiation

A waste paper sludge-derived heterogeneous catalyst（WPS-Fe-350） was synthesized via a facile method and successfully applied for the degradation of Orange Ⅱ in the presence of oxalic acid under the illumination of ultraviolet light emitting diode（UV-LED） Powder X-ray diffraction,Fourier-transform infrared spectroscopy,scanning electronic microscopy and N2 sorption isotherm analysis indicated the formation of α-Fe2O3 in the mesoporous nanocomposite.The degradation test showed that WPS-Fe-350 exhibited rapid Orange Ⅱ（OⅡ） degradation and mineralization in the presence of oxalic acid under the illumination of UV-LED.The effects of p H,oxalic acid concentration and dosage of the catalyst on the degradation of OⅡ were evaluated,respectively.Under the optimal conditions（1 g/L catalyst dosage,2 mmol/L oxalic acid and p H 3.0）,the degradation percentage for a solution containing 30 mg/L OⅡ reached 83.4% under illumination by UV-LED for 80 min.Moreover,five cyclic tests for OⅡ degradation suggested that WPS-Fe-350 exhibited excellent stability of catalytic activity.Hence,this study provides an alternative environmentally friendly way to reuse waste paper sludge and an effective and economically viable method for degradation of azo dyes and other refractory organic pollutants in water.