锡基、铜基氧化物表面结构调控及其在二氧化碳还原反应中的应用

Electrocatalytic redution of CO2 (CO2RR) into fuels not only could alleviate energy crisis, but also could improve global warming and greenhouse effect. To date, the main issue of catalysts for CO2RR is their high overpotential, low activity, as well as poor selectivity and stability. Metal oxide is a potential type of catalysts for CO2RR in aqueous solution. In this project, tin- and copper-based oxide (SnOx and CuOx) will be selected as study subjects. The project aims to enhance the activity and selectivity for formate/hydrocarbon, and decrease overpotential for CO2RR, through the fabrication of SnOx and CuOx nanocrystals with high energy facets. In the process of research, the growth mechanism of SnOx and CuOx nanocrystals with high energy facets will be studied, which is expected to provide guidance for design and synthesis of other metal oxide nanocrystals with high energy facets. In addition, efforts will also be directed to gain insight into the structure-activity relationship between the surface structure of SnOx and CuOx nanocrystals and activity and selectivity for CO2RR, and explore the reaction mechanism involved in the relevant processes through further surface analysis, in situ characterization, and theoretical calculation, thus providing guidance for the development of high efficient nanocatalysts for CO2RR.

将二氧化碳电还原（CO2RR）为燃料不仅有利于缓解能源危机，也有利于改善由二氧化碳导致的温室效应和全球变暖问题。目前，CO2RR催化剂的主要问题有过电位高、活性低、选择差和稳定性差。金属氧化物是一类具有潜力的能在水系电解液中电还原二氧化碳的催化剂。本项目拟以锡基和铜基氧化物（SnOx和CuOx）为研究对象，旨在通过可控制备出具有高能面裸露的SnOx和CuOx纳米晶来提高其CO2RR活性和甲酸盐/碳氢化合物产物的选择性，并降低过电位。在研究过程中，一方面，通过研究高能面裸露的SnOx和CuOx纳米晶的生长机理，为设计合成出其他高能面裸露的金属氧化物纳米晶提供理论指导。另一方面，通过进一步的表面分析和原位表征手段，结合理论计算，研究SnOx和CuOx纳米晶表面结构与CO2RR活性和产物选择性的构效关系，探究其反应机理，从而为发展高效CO2RR纳米催化剂提供一定的理论指导。

催化剂的表界面结构对催化活性起着重要作用。在本项目执行过程中，我们设计制备了一系列具有不同表界面结构的纳米催化剂，包括氧化亚铜 (Cu2O)，铂钴合金和二氧化铈负载的Au (Au/CeO2)。我们分别研究了高表面能裸露的Cu2O和铂钴合金纳米晶的生长机理，为设计合成出其他高能面裸露的纳米晶提供理论指导。我们进一步测试了Cu2O，铂钴合金和Au/CeO2 纳米催化剂分别在叠氮-炔烃的环加成反应，氧还原反应和电催化CO2还原反应中的催化性能。基于测试的催化性质，我们研究了纳米催化剂表界面结构与催化活性/选择性的构效关系。我们通过进一步的表面分析手段，探究了反应过程中的催化机理。这些研究为发展高效纳米催化剂提供一定的理论指导。