Unraveling the roles of atomically-dispersed Au in boosting photocatalytic CO_(2)reduction and aryl alcohol oxidation  

揭示原子级分散Au在促进光催化CO_(2)还原和芳香醇氧化中的作用

作　　者：Jian Lei Nan Zhou Shuaikang Sang Sugang Meng Jingxiang Low Yue Li 雷健;周楠;桑帅康;孟苏刚;刘敬祥;李越(淮北师范大学化学与材料科学学院,绿色和精准合成化学及应用教育部重点实验室,安徽省合成化学及应用重点实验室,安徽准北235000;中国科学技术大学化学与材料科学学院,合肥微尺度物质科学国家研究中心,安徽合肥230026;天津工业大学物理科学与技术学院,天津300387)

机构地区：[1]Key Laboratory of Green and Precise Synthetic Chemistry and Applications,Ministry of Education,Anhui Provincial Key Laboratory of Synthetic Chemistry and Applications,College of Chemistry and Materials Science,Huaibei Normal University,Huaibei 235000,Anhui,China [2]Hefei National Research Center for Physical Sciences at the Microscale,and School of Chemistry and Materials Science,University of Science and Technology of China,Hefei 230026,Anhui,China [3]School of Physical Science and Technology,Tiangong University,Tianjin 300387,China

出　　处：《Chinese Journal of Catalysis》2024年第10期163-173,共11页催化学报（英文）

基　　金：国家重点研发计划项目(2022YFE0126500);国家杰出青年科学基金项目(51825103);国家自然科学基金项目(92263209,52002142,22150610467,52261135635);安徽省杰出青年科学基金项目(2022AH020038).

摘　　要：Atomically-dispersed metal-based materials represent an emerging class of photocatalysts attributed to their high catalytic activity,abundant surface active sites,and efficient charge separation.Nevertheless,the roles of different forms of atomically-dispersed metals(i.e.,single-atoms and atomic clusters)in photocatalytic reactions remain ambiguous.Herein,we developed an ethylenediamine(EDA)-assisted reduction method to controllably synthesize atomically dispersed Au in the forms of Au single atoms(Au_(SA)),Au clusters(Au_(C)),and a mixed-phase of Au_(SA)and Au_(C)(Au_(SA+C))on CdS.In addition,we elucidate the synergistic effect of Au_(SA)and Au_(C)in enhancing the photocatalytic performance of CdS substrates for simultaneous CO_(2)reduction and aryl alcohol oxidation.Specifically,Au_(SA)can effectively lower the energy barrier for the CO_(2)→*COOH conversion,while Au_(C)can enhance the adsorption of alcohols and reduce the energy barrier for dehydrogenation.As a result,the Au_(SA)and Au_(C)co-loaded CdS show impressive overall photocatalytic CO_(2)conversion performance,achieving remarkable CO and BAD production rates of 4.43 and 4.71 mmol g^(−1)h^(−1),with the selectivities of 93%and 99%,respectively.More importantly,the solar-to-chemical conversion efficiency of Au_(SA+C)/CdS reaches 0.57%,which is over fivefold higher than the typical solar-to-biomass conversion efficiency found in nature(ca.0.1%).This study comprehensively describes the roles of different forms of atomically-dispersed metals and their synergistic effects in photocatalytic reactions,which is anticipated to pave a new avenue in energy and environmental applications.原子级分散金属由于其独特的电子结构、强金属载体相互作用和高比表面积,在光催化和电催化等领域中展现出较大的应用前景在光催化反应中,原子级分散金属不仅保留了金属纳米颗粒在光生载流子分离方面的优势,还额外提供了丰富的表面活性位点,从而提高了光催化反应的效率.尽管原子级分散金属在光催化中的研究发展迅速,但不同形式的原子级分散金属在增强光催化反应中的具体贡献仍存在争议.该挑战的核心在于难以实现对不同形式原子分散金属的可控合成,从而无法直接对比它们各自在增强光催化反应中的具体贡献.因此,系统研究原子级分散金属在光催化反应中的贡献对进一步扩展原子级分散金属的应用至关重要本文通过开发一种新的乙二胺辅助还原方法,为研究不同形式的原子分散金属(即单原子和原子团簇)在光催化反应中的作用建立了一个平台.具体而言,制备了负载有Au单原子(Au_(SA))、Au原子团簇(Au_(c))和Au单原子和团簇共存(Au_(SA+C))的CdS,用于光催化CO_(2)和苯甲醇(BA)的转化.通过粉末X射线衍射、X射线光电子能谱、CO吸附原位红外光谱、球差电镜和X射线吸收近边结构光谱验证了不同形式原子级分散Au的存在.在光催化CO_(2)还原和苯甲醇转化的耦合反应体系中,研究了不同类型原子分散型Au的作用及其协同效应.结果表明,当只有Au_(SA)存在时,CO_(2)转化为CO的选择性较高,但产率较低;当仅有Au_(c)存在时,BA的转化显著增强,但还原端的主要产物为H_(2).这表明Au_(SA)和Au_(c)在该耦合体系中各自独立发挥作用.而当Au_(SA)和Au_(c)共存时,二者产生了良好的协同效应,可同时实现CO_(2)和BA的高选择性转化.Au_(SA+C)的CO和苯甲醛(BAD)产率分别为4.43和4.71mmol g^(-1) h^(-1),选择性分别为93%和99%.更重要的是,Au_(SA+C)/CdS的太阳能-化学转化效率达到0.57%,比自然界中典型的�

关 键 词：Photocatalysis Atomically-dispersed metal SINGLE-ATOM CO_(2)reduction Aryl alcohol oxidation 

分 类 号：O62[理学—有机化学]