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Intrinsic pentagon defect engineering in multiple spatial-scale carbon frameworks for efficient triiodide reduction
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作者 Siyi Hou Xuedan Song +6 位作者 Chang Yu Jiangwei Chang Yiwang Ding Yingbin Liu Xiubo Zhang Weizhe Liu Jieshan Qiu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期20-28,I0002,共10页
Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon materials.However,the controllable construction of high-density and specific topologi... Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon materials.However,the controllable construction of high-density and specific topological defects in carbon frameworks to reveal the relationship between reactivity and defect structure remains a challenging task.Herein,the intrinsic pentagon carbon sites that can favor electron overflow and enhance their binding affinity towards the intermediates of catalytic reaction are firstly presented by the work function and the p-band center calculations.To experimentally verify this,the cage-opening reaction of fullerene is proposed and utilized for synthesizing carbon quantum dots with specific pentagon configuration(CQDs-P),subsequently utilizing CQDs-P to modulate the micro-scale defect density of three-dimensional reduced graphene oxide(rGO)viaπ-πinteractions.The multiple spatial-scale rGO-conjugated CQDs-P structure simultaneously possesses abundant pentagon and edge defects as catalytic active sites and long-range-orderedπelectron delocalization system as conductive network.The defects-rich CQDs-P/rGO-4 all-carbon-based catalyst exhibits superb catalytic activity for triiodide reduction reaction with a high photoelectric conversion efficiency of 8.40%,superior to the Pt reference(7.97%).Theoretical calculations suggest that pentagon defects in the carbon frameworks can promote charge transfer and modulate the adsorption/dissociation behavior of the reaction intermediates,thus enhancing the electrocatalytic activity of the catalyst.This work confirms the role of intrinsic pentagon defects in catalytic reactions and provides a new insight into the synthesis of defects-rich carbon catalysts. 展开更多
关键词 Defect engineering Pentagon carbon Carbon quantum dots Electrocatalytic activity Triiodide reduction
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Preparation of carbon fiber cloth supported porous CdS nanorods with excellent photocatalytic activity for Cr(Ⅵ)reduction
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作者 LI Hengchao WANG Wenguang +3 位作者 WU Liangpeng JIAN Siyuan LONG Shimin GUO Yuxi 《中南民族大学学报(自然科学版)》 CAS 2025年第1期9-21,共13页
The use of visible-light responsive photocatalysts for removing heavy metal ions in wastewater has received great attention.However,the development of photocatalysts with high activity and recyclability remains a huge... The use of visible-light responsive photocatalysts for removing heavy metal ions in wastewater has received great attention.However,the development of photocatalysts with high activity and recyclability remains a huge challenge.Herein,a recyclable carbon fiber cloth-supported porous CdS nanorod photocatalyst was fabricated by a two-step hydrothermal treatment using AgVO_(3) nanowires as templates.The results indicated that under visible-light illumination,the carbon cloth-supported porous CdS nanorods showed improved photocatalytic activity for the reduction of Cr(Ⅵ),with an apparent rate constant exceeding that of carbon cloth-supported CdS nanospheres by a factor of 1.65 times.Moreover,the carbon cloth-supported porous CdS nanorods can be easily separated and be reused.This brings a new perspective for developing photocatalysts with high efficiency and recyclability for wastewater treatment. 展开更多
关键词 carbon cloth cadmium sulfide silver metavanadate porous nanorods heavy metal ions reduction
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De novo-design of highly exposed Co−N−C single-atom catalyst for oxygen reduction reaction
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作者 ZHOU Dan ZHU Hongyue +1 位作者 ZHAO Yang LIU Yiming 《燃料化学学报(中英文)》 北大核心 2025年第1期128-137,共10页
The nitrogen-coordinated metal single-atom catalysts(M−N−C SACs)with an ultra-high metal loading synthetized by direct high-temperature pyrolysis have been widely reported.However,most of metal single atoms in these c... The nitrogen-coordinated metal single-atom catalysts(M−N−C SACs)with an ultra-high metal loading synthetized by direct high-temperature pyrolysis have been widely reported.However,most of metal single atoms in these catalysts were buried in the carbon matrix,resulting in a low metal utilization and inaccessibility for adsorption of reactants during the catalytic process.Herein,we reported a facile synthesis based on the hard-soft acid-base(HSAB)theory to fabricate Co single-atom catalysts with highly exposed metal atoms ligated to the external pyridinic-N sites of a nitrogen-doped carbon support.Benefiting from the highly accessible Co active sites,the prepared Co−N−C SAC exhibited a superior oxygen reduction reactivity comparable to that of the commercial Pt/C catalyst,showing a high turnover frequency(TOF)of 0.93 e^(−)·s^(-1)·site^(-1)at 0.85 V vs.RHE,far exceeding those of some representative SACs with a ultra-high metal content.This work provides a rational strategy to design and prepare M−N−C single-atom catalysts featured with high site-accessibility and site-density. 展开更多
关键词 hard-soft acid-base Co−N−C single-atom catalyst highly accessible active sites oxygen reduction reaction
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A post-modification strategy to precisely construct dual-atom sites for oxygen reduction electrocatalysis
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作者 Juan Wang Xinyan Liu +9 位作者 Chang-Xin Zhao Yun-Wei Song Jia-Ning Liu Xi-Yao Li Chen-Xi Bi Xin Wan Jianglan Shui Hong-Jie Peng Bo-Quan Li Jia-Qi Huang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期511-517,I0012,共8页
Dual-atom catalysts(DACs) afford promising potential for oxygen reduction electrocatalysis due to their high atomic efficiency and high intrinsic activity.However,precise construction of dual-atom sites remains a chal... Dual-atom catalysts(DACs) afford promising potential for oxygen reduction electrocatalysis due to their high atomic efficiency and high intrinsic activity.However,precise construction of dual-atom sites remains a challenge.In this work,a post-modification strategy is proposed to precisely fabricate DACs for oxygen reduction electrocatalysis.Concretely,a secondary metal precursor is introduced to the primary single-atom sites to introduce direct metal-metal interaction,which ensures the formation of desired atom pair structure during the subsequent pyrolysis process and allows for successful construction of DACs.The as-prepared FeCo-NC DAC exhibits superior oxygen reduction electrocatalytic activity with a half-wave potential of 0,91 V vs.reversible hydrogen electrode.Zn-air batteries equipped with the FeCo-NC DAC demonstrate higher peak power density than those with the Pt/C benchmark.More importantly,this post-modification strategy is demonstrated universal to achieve a variety of dual-atom sites.This work presents an effective synthesis methodology for precise construction of catalytic materials and propels their applications in energy-related devices. 展开更多
关键词 Dual-atom catalysts ELECTROCATALYSIS Oxygen reduction reaction Post-modification Zinc–air batteries
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Insights into Reduction of CO_(2) to CO Catalyzed by Pyramidal-4Ni Clusters Supported on Doped CeO_(2)
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作者 Ruimin Qin Shenyu Shen +4 位作者 Boyang Li Tingyi Zhu Tiantian Wu Shujiang Ding Yaqiong Su 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第5期591-598,I0028-I0037,I0099,共19页
Converting CO_(2) into valuable chemicals has become a widely used research method for CO_(2) conversion.In this work,the catalytic performance of pyramidal-4Ni catalysts supported on rare earth metal-doped CeO_(2)tow... Converting CO_(2) into valuable chemicals has become a widely used research method for CO_(2) conversion.In this work,the catalytic performance of pyramidal-4Ni catalysts supported on rare earth metal-doped CeO_(2)toward CO_(2) reductionreaction(CO_(2)RR)was investigated by using density-functional theorycalculations.For rare earth metal-doped CeO_(2),2Ce is substituted by 2 trivalent cations and at the same time one oxygen vacancy is created to make charge compensation.We investigated the oxygen vacancy nearest(Vo,N)and next-nearest(Vo,NN)to 4Ni,and found releasing CO and CO_(2) dissociation are the rate-determining steps,respectively,via the path of Vo,N and Vo,NN.Among the studied dopants(Ga,Sb,Lu,Gd,Pr,La,Bi),Gd is identified as the best dopant for catalyzing the reduction of CO_(2) at 823 K,with the turn-over frequency(TOF)of 104 times as large as that over 4Ni supported on pure CeO_(2).This exploration provides theoretical support and guidance for the research and application of rare earth metaldoped CeO_(2)-loaded Ni catalysts in the field of CO_(2) reduction. 展开更多
关键词 Carbon dioxide reduction CeO_(2)(111) Oxygen VACANCY Density functional theory
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Nickel-Nitrogen-Carbon(Ni-N-C)Electrocatalysts Toward CO_(2)electroreduction to CO:Advances,Optimizations,Challenges,and Prosoects
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作者 Qingqing Pang Xizheng Fan +7 位作者 Kaihang Sun Kun Xiang Baojun Li Shufang Zhao Young Dok Kim Qiaoyun Liu Zhongyi Liu Zhikun Peng 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第5期160-180,共21页
Electrocatalytic reduction of CO_(2)into high energy-density fuels and value-added chemicals under mild conditions can promote the sustainable cycle of carbon and decrease current energy and environmental problems.Con... Electrocatalytic reduction of CO_(2)into high energy-density fuels and value-added chemicals under mild conditions can promote the sustainable cycle of carbon and decrease current energy and environmental problems.Constructing electrocatalyst with high activity,selectivity,stability,and low cost is really matter to realize industrial application of electrocatalytic CO_(2)reduction(ECR).Metal-nitrogen-carbon(M-N-C),especially Ni-N-C,display excellent performance,such as nearly 100%CO selectivity,high current density,outstanding tolerance,etc.,which is considered to possess broad application prospects.Based on the current research status,starting from the mechanism of ECR and the existence form of Ni active species,the latest research progress of Ni-N-C electrocatalysts in CO_(2)electroreduction is systematically summarized.An overview is emphatically interpreted on the regulatory strategies for activity optimization over Ni-N-C,including N coordination modulation,vacancy defects construction,morphology design,surface modification,heteroatom activation,and bimetallic cooperation.Finally,some urgent problems and future prospects on designing Ni-N-C catalysts for ECR are discussed.This review aims to provide the guidance for the design and development of Ni-N-C catalysts with practical application. 展开更多
关键词 active sites CO_(2)reduction electrocatalysis Ni-N-C electrocatalysts optimization strategies
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Oxygen Reduction Reaction Activity of Fe-based Dual-Atom Catalysts with Different Local Configurations via Graph Neural Representation
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作者 Xueqian Xia Zengying Ma Yucheng Huang 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第5期599-604,I0038-I0040,I0099,共10页
The performance of proton exchange membrane fuel cells depends heavily on the oxygen reduction reaction(ORR)at the cathode,for which platinum-based catalysts are currently the standard.The high cost and limited availa... The performance of proton exchange membrane fuel cells depends heavily on the oxygen reduction reaction(ORR)at the cathode,for which platinum-based catalysts are currently the standard.The high cost and limited availability of platinum have driven the search for alternative catalysts.While FeN4 single-atom catalysts have shown promising potential,their ORR activity needs to be further enhanced.In contrast,dual-atom catalysts(DACs)offer not only higher metal loading but also the ability to break the ORR scaling relations.However,the diverse local structures and tunable coordination environments of DACs create a vast chemical space,making large-scale computational screening challenging.In this study,we developed a graph neural network(GNN)-based framework to predict the ORR activity of Fe-based DACs,effectively addressing the challenges posed by variations in local catalyst structures.Our model,trained on a dataset of 180 catalysts,accurately predicted the Gibbs free energy of ORR intermediates and overpotentials,and identified 32 DACs with superior catalytic activity compared to FeN4 SAC.This approach not only advances the design of high-performance DACs,but also offers a powerful computational tool that can significantly reduce the time and cost of catalyst development,thereby accelerating the commercialization of fuel cell technologies. 展开更多
关键词 Oxygen reduction reaction Dual-atom catalyst Graph neural representation Density functional theory Artificial intelligence
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Potential-dependent insights into the origin of high ammonia yield rate on copper surface via nitrate reduction:A computational and experimental study
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作者 Yangge Guo Nannan Sun +5 位作者 Liuxuan Luo Xiaojing Cheng Xueying Chen Xiaohui Yan Shuiyun Shen Junliang Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期272-281,共10页
Focusing on revealing the origin of high ammonia yield rate on Cu via nitrate reduction(NO3RR),we herein applied constant potential method via grand-canonical density functional theory(GC-DFT)with implicit continuum s... Focusing on revealing the origin of high ammonia yield rate on Cu via nitrate reduction(NO3RR),we herein applied constant potential method via grand-canonical density functional theory(GC-DFT)with implicit continuum solvation model to predict the reaction energetics of NO3RR on pure copper surface in alkaline media.The potential-dependent mechanism on the most prevailing Cu(111)and the minor(100)and(110)facets were established,in consideration of NO_(2)_(−),NO,NH_(3),NH_(2)OH,N_(2),and N_(2)O as the main products.The computational results show that the major Cu(111)is the ideal surface to produce ammonia with the highest onset potential at 0.06 V(until−0.37 V)and the highest optimal potential at−0.31 V for ammonia production without kinetic obstacles in activation energies at critical steps.For other minor facets,the secondary Cu(100)shows activity to ammonia from−0.03 to−0.54 V with the ideal potential at−0.50 V,which requires larger overpotential to overcome kinetic activation energy barriers.The least Cu(110)possesses the longest potential range for ammonia yield from−0.27 to−1.12 V due to the higher adsorption coverage of nitrate,but also with higher tendency to generate di-nitrogen species.Experimental evaluations on commercial Cu/C electrocatalyst validated the accuracy of our proposed mechanism.The most influential(111)surface with highest percentage in electrocatalyst determined the trend of ammonia production.In specific,the onset potential of ammonia production at 0.1 V and emergence of yield rate peak at−0.3 V in experiments precisely located in the predicted potentials on Cu(111).Four critical factors for the high ammonia yield and selectivity on Cu surface via NO3RR are summarized,including high NO3RR activity towards ammonia on the dominant Cu(111)facet,more possibilities to produce ammonia along different pathways on each facet,excellent ability for HER inhibition and suitable surface size to suppress di-nitrogen species formation at high nitrate coverage.Overall,our work provides comprehensive potential-dependent insights into the reaction details of NO3RR to ammonia,which can serve as references for the future development of NO3RR electrocatalysts,achieving higher activity and selectivity by maximizing these characteristics of copper-based materials. 展开更多
关键词 Nitrate reduction to ammonia Copper surface Density functional theory Constant electrode potential method Experimental validation
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Sulfur doped iron-nitrogen-hard carbon nanosheets as efficient and robust noble metal-free catalysts for oxygen reduction reaction in PEMFC
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作者 Bin Liu Jiawang Li +6 位作者 Bowen Yan Qi Wei Xingyu Wen Huarui Xie Huan He Pei Kang Shen Zhi Qun Tian 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期422-433,I0010,共13页
Transition metal-nitrogen-carbon(M-N-C)as a promising substitute for the conventional noble metalbased catalyst still suffers from low activity and durability for oxygen reduction reaction(ORR)in proton exchange membr... Transition metal-nitrogen-carbon(M-N-C)as a promising substitute for the conventional noble metalbased catalyst still suffers from low activity and durability for oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs).To tackle the issue,herein,a new type of sulfur-doped ironnitrogen-hard carbon(S-Fe-N-HC)nanosheets with high activity and durability in acid media were developed by using a newly synthesized precursor of amide-based polymer with Fe ions based on copolymerizing two monomers of 2,5-thiophene dicarboxylic acid(TDA)as S source and 1,8-diaminonaphthalene(DAN)as N source via an amination reaction.The as-synthesized S-Fe-N-HC features highly dispersed atomic Fe Nxmoieties embedded into rich thiophene-S doped hard carbon nanosheets filled with highly twisted graphite-like microcrystals,which is distinguished from the majority of M-N-C with soft or graphitic carbon structures.These unique characteristics endow S-Fe-N-HC with high ORR activity and outstanding durability in 0.5 M H_(2)SO_(4).Its initial half-wave potential is 0.80 V and the corresponding loss is only 21 m V after 30,000 cycles.Meanwhile,its practical PEMFC performance is a maximum power output of 628.0 mW cm^(-2)and a slight power density loss is 83.0 m W cm^(-2)after 200-cycle practical operation.Additionally,theoretical calculation shows that the activity of Fe Nxmoieties on ORR can be further enhanced by sulfur doping at meta-site near FeN_(4)C.These results evidently demonstrate that the dual effect of hard carbon substrate and S doping derived from the precursor platform of amid-polymers can effectively enhance the activity and durability of Fe-N-C catalysts,providing a new guidance for developing advanced M-N-C catalysts for ORR. 展开更多
关键词 Transition metal-nitrogen-carbon Oxygen reduction reaction Hard carbon Amide based polymer reaction Proton exchange membrane cells
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Chalcogen heteroatoms doped nickel-nitrogen-carbon single-atom catalysts with asymmetric coordination for efficient electrochemical CO_(2) reduction
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作者 Jialin Wang Kaini Zhang +5 位作者 Ta Thi Thuy Ng Yiqing Wang Yuchuan Shi Daixing Wei Chung-Li Dong Shaohua Shen 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第9期54-65,共12页
The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO_(2) reduction reaction(eCO_(2)RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into... The electronic configuration of central metal atoms in single-atom catalysts(SACs)is pivotal in electrochemical CO_(2) reduction reaction(eCO_(2)RR).Herein,chalcogen heteroatoms(e.g.,S,Se,and Te)were incorporated into the symmetric nickel-nitrogen-carbon(Ni-N_(4)-C)configuration to obtain Ni-X-N_(3)-C(X:S,Se,and Te)SACs with asymmetric coordination presented for central Ni atoms.Among these obtained Ni-X-N_(3)-C(X:S,Se,and Te)SACs,Ni-Se-N_(3)-C exhibited superior eCO_(2)RR activity,with CO selectivity reaching~98% at-0.70 V versus reversible hydrogen electrode(RHE).The Zn-CO_(2) battery integrated with Ni-Se-N_(3)-C as cathode and Zn foil as anode achieved a peak power density of 1.82 mW cm^(-2) and maintained remarkable rechargeable stability over 20 h.In-situ spectral investigations and theoretical calculations demonstrated that the chalcogen heteroatoms doped into the Ni-N_(4)-C configuration would break coordination symmetry and trigger charge redistribution,and then regulate the intermediate behaviors and thermodynamic reaction pathways for eCO_(2)RR.Especially,for Ni-Se-N_(3)-C,the introduced Se atoms could significantly raise the d-band center of central Ni atoms and thus remarkably lower the energy barrier for the rate-determining step of ^(*)COOH formation,contributing to the promising eCO_(2)RR performance for high selectivity CO production by competing with hydrogen evolution reaction. 展开更多
关键词 Electrochemical CO_(2) reduction reaction Chalcogen heteroatoms Single-atom catalysts Asymmetric coordination CO production
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Metal-N_(4) model single‐atom catalyst with electroneutral quadri‐pyridine macrocyclic ligand for CO_(2) electroreduction
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作者 Jian‐Zhao Peng Yin‐Long Li +7 位作者 Yao‐Ti Cheng Fu‐Zhi Li Bo Cao Qing Wang Xian Yue Guo‐Tao Lai Yang‐Gang Wang Jun Gu 《Carbon Energy》 SCIE EI CAS CSCD 2024年第8期122-133,共12页
Metal–N–C single‐atom catalysts,mostly prepared from pyrolysis of metalorganic precursors,are widely used in heterogeneous electrocatalysis.Since metal sites with diverse local structures coexist in this type of ma... Metal–N–C single‐atom catalysts,mostly prepared from pyrolysis of metalorganic precursors,are widely used in heterogeneous electrocatalysis.Since metal sites with diverse local structures coexist in this type of material and it is challenging to characterize the local structure,a reliable structure–property relationship is difficult to establish.Conjugated macrocyclic complexes adsorbed on carbon support are well‐defined models to mimic the singleatom catalysts.Metal–N_(4) site with four electroneutral pyridine‐type ligands embedded in a graphene layer is the most commonly proposed structure of the active site of single‐atom catalysts,but its molecular counterpart has not been reported.In this work,we synthesized the conjugated macrocyclic complexes with a metal center(Co,Fe,or Ni)coordinated with four electroneutral pyridinic ligands as model catalysts for CO_(2) electroreduction.For comparison,the complexes with anionic quadri‐pyridine macrocyclic ligand were also prepared.The Co complex with the electroneutral ligand expressed a turnover frequency of CO formation more than an order of magnitude higher than that of the Co complex with the anionic ligand.Constrained ab initio molecular dynamics simulations based on the well‐defined structures of the model catalysts indicate that the Co complex with the electroneutral ligand possesses a stronger ability to mediate electron transfer from carbon to CO_(2). 展开更多
关键词 ab initio molecular dynamics CO_(2)reduction electrocatalysis model catalyst single‐atom catalyst
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Recent Advances in Transition Metal-Based Catalysts for Electrocatalytic Nitrate Reduction Reaction
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作者 LUO Hongxia CHEN Jun YANG Jianping 《Journal of Donghua University(English Edition)》 CAS 2024年第4期333-348,共16页
The accumulation of excessive nitrate in the atmosphere not only jeopardizes human health but also disrupts the balance of the nitrogen cycle in the ecosystem.Among various nitrate removal technologies,electrocatalyti... The accumulation of excessive nitrate in the atmosphere not only jeopardizes human health but also disrupts the balance of the nitrogen cycle in the ecosystem.Among various nitrate removal technologies,electrocatalytic nitrate reduction reaction(eNO_(3)RR)has been widely studied for its advantages of being eco-friendly,easy to operate,and controllable under environmental conditions with renewable energy as the driving force.Transition metal-based catalysts(TMCs)have been widely used in electrocatalysis due to their abundant reserves,low costs,easy-to-regulate electronic structure and considerable electrochemical activity.In addition,TMCs have been extensively studied in terms of the kinetics of the nitrate reduction reaction,the moderate adsorption energy of nitrogen-containing species and the active hydrogen supply capacity.Based on this,this review firstly discusses the mechanism as well as analyzes the two main reduction products(N_(2)and NH_(3))of eNO_(3)RR,and reveals the basic guidelines for the design of efficient nitrate catalysts from the perspective of the reaction mechanism.Secondly,this review mainly focuses on the recent advances in the direction of eNO_(3RR)with four types of TMCs,Fe,Co,Ni and Cu,and unveils the interfacial modulation strategies of Fe,Co,Ni and Cu catalysts for the activity,reaction pathway and stability.Finally,reasonable suggestions and opportunities are proposed for the challenges and future development of eNO_(3)RR.This review provides far-reaching implications for exploring cost-effective TMCs to replace high-cost noble metal catalysts(NMCs)for eNO_(3)RR. 展开更多
关键词 electrocatalysis nitrate reduction reaction transition metal-based catalyst(TMC) reaction mechanism nitrogen cycle
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A novel metal-free porous covalent organic polymer for efficient room-temperature photocatalytic CO_(2) reduction via dry-reforming of methane
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作者 Sheng-Yan Yin Ziyi Li +2 位作者 Yingcai Hu Xiao Luo Jishan Li 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第9期1407-1418,共12页
At room temperature,the conversion of greenhouse gases into valuable chemicals using metal-free catalysts for dry reforming of methane(DRM) is quite promising and challenging.Herein,we developed a novel covalent organ... At room temperature,the conversion of greenhouse gases into valuable chemicals using metal-free catalysts for dry reforming of methane(DRM) is quite promising and challenging.Herein,we developed a novel covalent organic porous polymer (TPE-COP) with rapid charge separation of the electron–hole pairs for DRM driven by visible light at room temperature,which can efficiently generate syngas (CO and H_(2)).Both electron donor (tris(4-aminophenyl)amine,TAPA) and acceptor (4,4',4'',4'''-((1 E,1'E,1''E,1'''E)-(ethene-1,1,2,2-tetrayltetrakis (benzene-4,1-diyl))tetrakis (ethene-2,1-diyl))tetrakis (1-(4-formylbenzyl)quinolin-1-ium),TPE-CHO) were existed in TPE-COP,in which the push–pull effect between them promoted the separation of photogenerated electron–hole,thus greatly improving the photocatalytic activity.Density functional theory (DFT) simulation results show that TPE-COP can form charge-separating species under light irradiation,leading to electrons accumulation in TPE-CHO unit and holes in TAPA,and thus efficiently initiating DRM.After 20 h illumination,the photocatalytic results show that the yields reach 1123.6 and 30.8μmol g^(-1)for CO and H_(2),respectively,which are significantly higher than those of TPE-CHO small molecules.This excellent result is mainly due to the increase of specific surface area,the enhancement of light absorption capacity,and the improvement of photoelectron-generating efficiency after the formation of COP.Overall,this work contributes to understanding the advantages of COP materials for photocatalysis and fundamentally pushes metal-free catalysts into the door of DRM field. 展开更多
关键词 METAl-FREE Photocatalytic CO_(2)reduction Covalent organic polymer Dry-reforming of methane Electron donor and acceptor
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Experimental Study on Ammonia Co-Firing with Coal for Carbon Reduction in the Boiler of a 300-MW Coal-Fired Power Station
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作者 Qifu Lin Wangping Sun +15 位作者 Haiyan Li Yangjiong Liu Yuwei Chen Chengzhou Liu Yiman Jiang Yu Cheng Ning Ma Huaqing Ya Longwei Chen Shidong Fang Hansheng Feng Guang-Nan Luo Jiangang Li Kaixin Xiang Jie Cong Cheng Cheng 《Engineering》 SCIE EI CAS CSCD 2024年第9期247-259,共13页
To reduce CO_(2) emissions from coal-fired power plants,the development of low-carbon or carbon-free fuel combustion technologies has become urgent.As a new zero-carbon fuel,ammonia(NH_(3))can be used to address the s... To reduce CO_(2) emissions from coal-fired power plants,the development of low-carbon or carbon-free fuel combustion technologies has become urgent.As a new zero-carbon fuel,ammonia(NH_(3))can be used to address the storage and transportation issues of hydrogen energy.Since it is not feasible to completely replace coal with ammonia in the short term,the development of ammonia-coal co-combustion technology at the current stage is a fast and feasible approach to reduce CO_(2) emissions from coal-fired power plants.This study focuses on modifying the boiler and installing two layers of eight pure-ammonia burners in a 300-MW coal-fired power plant to achieve ammonia-coal co-combustion at proportions ranging from 20%to 10%(by heat ratio)at loads of 180-to 300-MW,respectively.The results show that,during ammonia-coal co-combustion in a 300-MW coal-fired power plant,there was a more significant change in NO_(x) emissions at the furnace outlet compared with that under pure-coal combustion as the boiler oxygen levels varied.Moreover,ammonia burners located in the middle part of the main combustion zone exhibited a better high-temperature reduction performance than those located in the upper part of the main combustion zone.Under all ammonia co-combustion conditions,the NH_(3) concentration at the furnace outlet remained below 1 parts per million(ppm).Compared with that under pure-coal conditions,the thermal efficiency of the boiler slightly decreased(by 0.12%-0.38%)under different loads when ammonia co-combustion reached 15 t·h^(-1).Ammonia co-combustion in coal-fired power plants is a potentially feasible technology route for carbon reduction. 展开更多
关键词 Coal-fired boiler Coal mixing with ammonia Ammonia-coal co-firing Nitrogen oxide(NO_(x)) CO_(2)reduction Boiler thermal efficiency
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Enhanced CO_(2)electroreduction to ethylene via strong metal-support interaction 被引量:5
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作者 Mengen Chu Chunjun Chen +6 位作者 Yahui Wu Xupeng Yan Shuaiqiang Jia Ruting Feng Haihong Wu Mingyuan He Buxing Han 《Green Energy & Environment》 SCIE EI CSCD 2022年第4期792-798,共7页
The CuO/CeO_(2) composites with strong metal-support interaction were synthesised,which can efficiently electroreduct CO_(2)to C(2)H_(4).The Faradaic efficiency(FE)of C_(2)H_(4) could reach 50.5%with a current density... The CuO/CeO_(2) composites with strong metal-support interaction were synthesised,which can efficiently electroreduct CO_(2)to C(2)H_(4).The Faradaic efficiency(FE)of C_(2)H_(4) could reach 50.5%with a current density of 18 mA cm^(-2).The strong metal-support interaction could not only enhance the adsorption and activation of CO_(2),but also can stablize the CuO. 展开更多
关键词 Carbon dioxide reduction Ethyene ELECTROCATALYST Copper-ceria interaction
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Copper and platinum dual-single-atoms supported on crystalline graphitic carbon nitride for enhanced photocatalytic CO_(2) reduction 被引量:17
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作者 Lei Cheng Peng Zhang +2 位作者 Qiye Wen Jiajie Fan Quanjun Xiang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第2期451-460,共10页
Single-atom Pt catalysts are designed to promote efficient atom utilization,whereas effective decrease of Pt loading and improvement of photocatalytic activity in monoatomic Pt-deposited systems is still ongoing.Atomi... Single-atom Pt catalysts are designed to promote efficient atom utilization,whereas effective decrease of Pt loading and improvement of photocatalytic activity in monoatomic Pt-deposited systems is still ongoing.Atomically dispersed metal species in crystalline carbon nitride are still challenging owing to their high crystallization and structural stability.In this study,we developed a novel single-atomic Pt-Cu catalyst for reducing noble metal loading by combining Pt with earth-abundant Cu atoms and enhancing photocatalytic CO_(2)reduction.N-vacancy-rich crystalline carbon nitride was used as a fine-tuning ligand for isolated Pt-Cu atom dispersion based on its accessible functional N vacancies as the seeded centers.The synthesized dimetal Pt-Cu atoms on crystalline carbon nitride(Pt Cu-cr CN)exhibited high selectivity and activity for CO_(2)conversion without the addition of any cocatalyst or sacrificial agent.In particular,we demonstrated that the diatomic Pt-Cu exhibited high mass activity with only 0.32 wt% Pt loading and showed excellent photocatalytic selectivity toward CH_(4)generation.The mechanism of CO_(2)photoreduction for Pt Cu-cr CN was proposed based on the observations and analysis of aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images,in situ irradiated X-ray photoelectron spectroscopy,and in situ diffuse reflectance infrared Fourier transform spectroscopy.The findings of this work provide insights for abrogating specific bifunctional atomic metal sites in noble metal-based photocatalysts by reducing noble metal loading and maximizing their effective mass activity. 展开更多
关键词 Dimetal Pt-Cu atom Crystalline carbon nitride Photocatalytic CO_(2)reduction Low loading Synergistic photocatalysis
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Solar-heating boosted catalytic reduction of CO_(2) under full-solar spectrum 被引量:2
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作者 Hongjia Wang Yanjie Wang +3 位作者 Lingju Guo Xuehua Zhang Caue Ribeiro Tao He 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第1期131-139,共9页
Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low e... Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low efficiency due to narrow solar-spectrum utilization and sluggish heterogeneous reaction kinetics.In this work,we demonstrate that catalytic reduction of CO2 can be achieved over Au nanoparticles(NPs)deposited rutile under full solar-spectrum irradiation,boosted by solar-heating effect.We found that UV and visible light can initiate the reaction,and the heat from IR light and local surface-plasmon resonance relaxation of Au NPs can boost the reaction kinetically.The apparent activation energy is determined experimentally and is used to explain the superior catalytic activity of Au/rutile to rutile in a kinetic way.We also find the photo-thermal synergy in the Au/rutile system.We envision that this work may facilitate understanding the kinetics of CO2 reduction and developing feasible catalytic systems with full solar spectrum utilization for practical artificial photosynthesis. 展开更多
关键词 CO_(2) reduction Apparent activation energy Reaction kinetics Solar heating Photo-thermal synergy
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Dual-site collaboration boosts electrochemical nitrogen reduction on Ru-S-C single-atom catalyst 被引量:2
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作者 Liujing Yang Chuanqi Cheng +8 位作者 Xun Zhang Cheng Tang Kun Du Yuanyuan Yang Shan-Cheng Shen Shi-Long Xu Peng-Fei Yin Hai-Wei Liang Tao Ling 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第12期3177-3186,共10页
Electrocatalytic reduction of nitrogen into ammonia(NH_(3))is a highly attractive but challenging route for NH_(3)production.We propose to realize a synergetic work of multi reaction sites to overcome the limitation o... Electrocatalytic reduction of nitrogen into ammonia(NH_(3))is a highly attractive but challenging route for NH_(3)production.We propose to realize a synergetic work of multi reaction sites to overcome the limitation of sustainable NH_(3)production.Herein,using ruthenium-sulfur-carbon(Ru-S-C)catalyst as a prototype,we show that the Ru/S dual-site cooperates to catalyse eletrocatalytic nitrogen reduction reaction(eNRR)at ambient conditions.With the combination of theoretical calculations,in situ Raman spectroscopy,and experimental observation,we demonstrate that such Ru/S dual-site cooperation greatly facilitates the activation and first protonation of N_(2)in the rate-determining step of eNRR.As a result,Ru-S-C catalyst exhibits significantly enhanced eNRR performance compared with the routine Ru-N-C catalyst via a single-site catalytic mechanism.We anticipate that our specifically designed dual-site collaborative catalytic mechanism will open up a new way to offers new opportunities for advancing sustainable NH_(3)production. 展开更多
关键词 Ru/S dual-site mechanism Electronic‘push-push’mechanism Electrocatalytic nitrogen reduction reaction
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Preparation of primary Al-Si alloy from bauxite tailings by carbothermal reduction process 被引量:4
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作者 杨栋 冯乃祥 +1 位作者 王耀武 武小雷 《中国有色金属学会会刊:英文版》 CSCD 2010年第1期147-152,共6页
Effects of various reaction parameters such as atmospheric pressure, treating temperature, sintering time and bituminite content on the preparation of primary Al-Si alloy by carbothermal reduction of bauxite tailings ... Effects of various reaction parameters such as atmospheric pressure, treating temperature, sintering time and bituminite content on the preparation of primary Al-Si alloy by carbothermal reduction of bauxite tailings were investigated by XRD,XRF, infrared absorption carbon-sulfur analysis unit and SEM coupled with EDS. Meanwhile, the mechanism of carbothermal reduction of Al2O3 and SiO2 was discussed. It is found that pressure and temperature are major factors that influence the carbothermal reduction of bauxite tailings. The appropriate conditions for preparation of primary Al-Si alloy are as follows: atmospheric pressure of 0.1 MPa, heating temperature of 1 900 ℃,bituminite content of 95% (mass fraction) of theoretic bituminite content and sintering time of 1 h. Among four mechanisms of carbothermal reduction of Al2O3 and SiO2, the theory of the formation and decomposition of carbides might be the best one to interpret the reaction process. 展开更多
关键词 碳热还原 铝硅合金 合金制备 铝土矿 还原过程 尾矿 X射线荧光光谱 Al2O3
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Effect of structural characteristics distribution on strength demand and ductility reduction factor of MDOF systems considering soil-structure interaction
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作者 Behnoud Ganjavi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2012年第2期205-220,共16页
It is known that structural stiffness and strength distributions have an important role in the seismic response of buildings. The effect of using different code-specified lateral load patterns on the seismic performan... It is known that structural stiffness and strength distributions have an important role in the seismic response of buildings. The effect of using different code-specified lateral load patterns on the seismic performance of fixed-base buildings has been investigated by researchers during the past two decades. However, no investigation has yet been carried out for the case of soil-structure systems. In the present study, through intensive parametric analyses of 21,600 linear and nonlinear MDOF systems and considering five different shear strength and stiffness distribution patterns, including three code-specified patterns as well as uniform and concentric patterns subjected to a group of earthquakes recorded on alluvium and soft soils, the effect of structural characteristics distribution on the strength demand and ductility reduction factor of MDOF fixed-base and soil-structure systems are parametrically investigated. The results of this study show that depending on the level of inelasticity, soil flexibility and number of degrees-of-freedoms (DOFs), structural characteristics distribution can significantly affect the strength demand and ductility reduction factor of MDOF systems. It is also found that at high levels of inelasticity, the ductility reduction factor of low-rise MDOF soil-structure systems could be significantly less than that of fixed-base structures and the reduction is less pronounced as the number of stories increases. 展开更多
关键词 soil-structure interaction MDOF systems structural characteristic distribution inelastic behavior strength demand ductility reduction factor
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