光催化二氧化碳还原制多碳产物的先进光催化剂设计与机制:现状与挑战

Rational design and mechanistic insights of advanced photocatalysts for CO_(2)‐to‐C_(2+) production:Status and challenges

在可持续碳资源利用的研究中,光催化CO_(2)转化为高附加值化学品的前景日益凸显.相较于常见的CO_(2)还原产物如甲烷、一氧化碳或甲酸,具有两个或更多碳原子的C_(2+)化合物因其具有更高的附加值而备受关注.然而,目前的研究面临着C–C偶联过程和多质子耦合电子转移效率的限制,导致光催化CO_(2)的还原反应产物主要为C1化合物.常规光催化剂难以突破这些动力学和热力学壁垒,导致目标产物C_(2+)化合物的生成量远低于实际工业应用所需要的水平.因此,开发具有良好性能的光催化剂,以实现C_(2+)化合物的高效制备,仍是当前面临的重要科学挑战.本文系统性地概述了光催化CO_(2)还原为C_(2+)化合物领域的最新研究进展.首先,从光催化的基本原理及C_(2+)产物的生成路径出发,在光催化剂设计方面,为突破C–C偶联和多质子耦合电子转移的限制,需要解决以下问题:(1)关键中间产物的生成与吸附转移;(2)活性位点对于中间产物的选择性;(3)光生电子的寿命与定向转移.随后,详细介绍了高效、高选择性光催化剂的合理设计策略,包括缺陷工程、双金属位点、表面等离子体共振以及异质结构造等.同时,深入探讨了C–C偶联和多电子偶联的质子转移过程的催化机制.最后,展望了光催化CO_(2)还原制C_(2+)高附加值产物的未来研究方向,催化剂设计与机制研究的关键方向包括:(1)设计高选择性和高效吸附*CO中间体的活性位点,以提升催化性能;(2)设计具有轨道匹配的双活性位点以减少邻近*CO中间体间的静电排斥,促进C–C耦合;(3)从分子轨道相互作用角度深入理解C–C耦合和电子转移过程,揭示反应机制;(4)鉴别反应过程中的自由基组分,阐明多质子耦合电子转移过程的机理.综上所述,本文系统地梳理了光催化CO_(2)还原制C_(2+)高附加值产物的研究进展、关键问题、催化剂设计原理以及未来研究方向,旨在为开发设计高效、高选择性催化剂提供有益的参考.

Photocatalytic CO_(2) conversion into high-value chemicals is becoming an increasingly promising avenue of research in the quest for sustainable carbon resource utilization.Particularly,compounds with two or more carbons(C_(2+))have higher added value than methane,carbon monoxide,or formate,which are typically the major products of CO_(2) reduction.In this review,we present a detailed account of recent advancements in the field of photocatalytic CO_(2) conversion,with a specific focus on the synthesis of multi-carbon oxygenates.We systematically introduce the rational design of photocatalysts with high effectivity and selectivity,which follows a methodical inside-to-outside order.These strategies consider various aspects of photocatalyst optimization,from the core structure to the surface properties.Meanwhile,we delve into an in-depth analysis of the underlying catalytic mechanisms,particularly emphasizing the C-C coupling and multi-electron-coupled proton transfer processes.Lastly,we examine the prospects and challenges in developing photocatalysts for CO_(2) conversion,providing valuable insights for researchers and practitioners.This review aims to serve as a valuable resource for those seeking to design advanced catalysts for efficient photocatalytic CO_(2) reduction.