Engineering tandem catalysts and reactors for promoting electrocatalytic CO₂ reduction reaction toward multi‑carbon products

Electrocatalytic CO₂ reduction reaction (eCO₂RR) is one of the most promising pathways to alleviate the global greenhouse effects while simultaneously producing value-added chemicals. In recent years, multi‑carbon (C₂₊) products synthesized by eCO₂RR have attracted increasing attention because of their high energy density and a broad range of practical usage. Unfortunately, the selectivity, stability, and energy efficiency of eCO₂RR for achieving single C₂₊ product are still far too low to meet the standards of industrial production. The tandem CO₂ electrocatalysis has demonstrated promising potential to boost the formation of C₂₊ products, in which the C—C coupling energy barrier could be efficiently decreased through the enrichment of intermediates. However, solely focusing on the design of tandem electrocatalysts is insufficient to produce long-chain hydrocarbons in a large scale. Herein, this review summarizes, in addition to the comprehensive analysis of the recent fine design of tandem CO₂ electrocatalysts, the latest research progress of tandem reactors for the eCO₂RR. The current problems, potential solutions and perspective development directions of CO₂ tandem electrolysis in the future are also discussed. It aims to provide a fundamental springboard for improving the selectivity of C₂₊ products and, more importantly, push forward the ultimate performance for reaching industrial synthesis of C₂₊ products. © 2023 Elsevier B.V.