单原子催化剂在电催化还原CO_(2)领域的应用

Electrocatalytic CO_(2) Reduction over Single-atom Catalysts

温和条件下以CO_(2)为原料制备高附加值化学品,是CO_(2)资源化利用的重要方法,在众多CO_(2)转化方法中,电催化CO_(2)还原(e-CO_(2)RR)具有绿色、清洁及条件可控等优势,可以促进碳中和,实现可持续发展.然而,由于其缓慢的动力学和较低催化剂活性, CO_(2)电催化还原仍然存在低选择性,低电流密度的问题.单原子催化剂具有最大的原子利用率和明确定义的催化活性位点,同时因其良好的配位结构和独特的电子结构极大地促进了CO_(2)电催化还原的动力学过程,是CO_(2)电还原领域极具发展潜力的催化材料.本文讨论了过渡金属和主族金属基单原子催化剂用于电催化CO_(2)还原的研究进展,系统总结了杂原子配位,双/单原子位点,金属-载体相互作用,空间限域和分子桥联等策略调控单原子的微环境进而优化催化的性能,揭示了单原子催化剂在e-CO_(2)RR领域内的突出优势和广阔的应用前景.最后,分析了单原子催化剂在CO_(2)电催化转化过程中面临的挑战,并对其未来进行了展望.

Electrochemical CO_(2)reduction reaction(e-CO_(2)RR)is a promising and facile method to achieve carbonneutral economy and sustainable development due its simple device and capability to consume renewable energy to produce high value-added chemicals. However,e-CO_(2)RR suffers from low selectivity and low current density because of its sluggish kinetics and the weak activity of the catalysts. Hence,single-atom catalysts are one of the most ideal materials for e-CO_(2)RR by virtue of its maximum atom utilization and well-defined catalytic active sites. Single atoms derived from transition metal and main group metal are comprehensively reviewed. Heteroatom coordination,dual-atom site,metal-support interactions,spatial confinement and molecular bridging to tailor the microenvironment of single atom to realize a better catalytic performance are also included. Single-atom catalysts extremely accelerate electrocatalytic CO_(2)reduction kinetics,which is ascribed to its unique electronic structure and enormous intrinsic highly active sites,indicating its state-of-the-art merits and broad application prospects. Reductive products that involve multi-electrons are desired for single-atom catalysts. Finally,research trends and hotspots in this field are also discussed.