基于限域效应构筑高性能CO2电化学还原纳米催化剂的研究

The development of nanocatalysts with high activity, selectivity and stability for electrochemical reduction of CO2 is the key challenge for the efficient utilization of CO2. This proposal will focus on the fabrication of high-performance nanocatalysts for efficient electrochemical reduction of CO2 by space-confinement effects. On one hand, the proposal will prepare the well-dispersed nanocatalysts with the controllable size in several nanometer scale, adjustable microstructure and surface properties by using the space-confinement effects from the micropores or microchannels in the nanocarbon-based catalyst supports and the inter-lamellar spaces in two-dimensional nanomaterials. With this approach, the activity and selectivity of the nanocatalysts for electrochemical reduction of CO2 can be effectively enhanced through the decrease in the coordination number of active sites, the increase in the quantity of active sites, the fabrication of multi-component nanocatalysts, as well as the synergetic effects between confined microspaces and active sites. On the other hand, it is expected that the stability of nanocatalysts can be effectively improved by the physical confinement and the chemical interaction between confined microspaces and active sites. Furthermore, together with the theoretic computation and analysis, the proposal will reveal the relationships between the microstructure, size, and surface properties of nanocatalysts and their activity, selectivity and stability for electrochemical reduction of CO2, thus understand the catalytic mechanism in the process. Based on the above results, it is expected to achieve the high-performance nanocatalysts for efficient electrochemical reduction of CO2.

开发高活性、高选择性与高稳定性的电化学还原CO2催化剂是利用可再生能源实现CO2高效利用的关键。本项目拟基于限域效应来设计与可控构筑高活性、高稳定性的电化学还原CO2纳米催化剂。一方面，利用载体中构建的微孔道与二维层状材料层间微空间的限域效应，构筑高度分散的、尺寸、结构、组成及表面微观特性可调的纳米催化剂；通过降低催化活性中心的配位数，增加活性中心数量，构筑复合催化剂，调控载体限域微空间与催化活性中心之间的相互作用，结合组分调控，来调节催化中心对反应中间体及产物的吸附与还原能力，进而降低CO2还原超电势并抑制催化剂的析氢活性，提高催化剂还原CO2的活性，优化产物选择性。另一方面，通过物理限域效应以及限域微空间与小尺寸纳米催化剂之间的化学相互作用有效地提高催化剂的稳定性。此外，结合相关理论计算，揭示电催化还原CO2纳米催化剂微观结构、表面特性与其活性、选择性及稳定性之间的构效关系，理解催化反应机制，反馈指导催化剂的调控，最终获得高性能的电化学还原CO2纳米催化剂。

开发高性能的电化学还原CO2催化剂是利用可再生能源实现CO2电化学转化和高效利用的关键。项目组主要基于限域效应来设计与可控构筑高活性、高选择性和高稳定性的电化学还原CO2纳米催化剂。构建了多种具有可调纳米级限域空间的碳基载体；通过限域作用构筑了系列高度分散、尺寸可调、活性位点密度高的纳米催化剂；系统研究了限域效应和载体强相互作用对催化剂微观结构、电子结构和表面特性的影响；揭示了其与电化学还原CO2性能间的构效关系；结合理论计算和分子模型催化剂设计阐释了催化活性机制；发展了显著提升催化剂性能的策略；获得了多种高活性、高选择性和高稳定性的催化剂，实现了CO2到CO、甲酸、乙酸和乙烯的高效选择性电化学转化。. 通过项目的实施，已经发表SCI收录学术论文31篇，其中1区论文29篇，包括2篇Angew. Chem.、1篇Nat. Commun.和3篇JACS等。6研究论文入选ESI热点和/或高被引研究论文。申请中国发明专利6项，已授权2项。培养博士研究生6名，其中一名获得博士后创新人才支持计划资助。受邀参加MRS和ACS年会等国内外学术会议并做邀请报告8次。