Designs of Tandem Catalysts and Cascade Catalytic Systems for CO<sub>2</sub> Upgrading
Wanzhen Zheng, Xiaoxuan Yang, Zhongjian Li, Bin Yang, Qinghua Zhang, Lecheng Lei, Yang Hou
Abstract
Abstract Upgrading CO 2 into multi‐carbon (C2+) compounds through the CO 2 reduction reaction (CO 2 RR) offers a practical approach to mitigate atmospheric CO 2 while simultaneously producing high value chemicals. The reaction pathways for C2+ production involve multi‐step proton‐coupled electron transfer (PCET) and C−C coupling processes. By increasing the surface coverage of adsorbed protons (*H ad ) and *CO intermediates, the reaction kinetics of PCET and C−C coupling can be accelerated, thereby promoting C2+ production. However, *H ad and *CO are competitively adsorbed intermediates on monocomponent catalysts, making it difficult to break the linear scaling relationship between the adsorption energies of the *H ad /*CO intermediate. Recently, tandem catalysts consisting of multicomponents have been developed to improve the surface coverage of *H ad or *CO by enhancing water dissociation or CO 2 ‐to‐CO production on auxiliary sites. In this context, we provide a comprehensive overview of the design principles of tandem catalysts based on reaction pathways for C2+ products. Moreover, the development of cascade CO 2 RR catalytic systems that integrate CO 2 RR with downstream catalysis has expanded the range of potential CO 2 upgrading products. Therefore, we also discuss recent advancements in cascade CO 2 RR catalytic systems, highlighting the challenges and perspectives in these systems.