Electrocatalytic reduction of CO2 to produce the C2+ products: from selectivity to rational catalyst design

Electrocatalytic reduction of CO2 (eCO2RR) into valuable multi-carbon (C2+) products is an effective strategy for combating climate change and mitigating energy crises. The high-energy density and diverse applications of C2+ products have attracted considerable interest. However, the complexity of the reaction pathways and the high energy barriers to C-C coupling lead to lower selectivity and faradaic efficiency for C2+ products than for C1 products. Therefore, a thorough understanding of the underlying mechanisms and identification of reaction conditions that influence selectivity, followed by the rational design of catalysts, are considered promising methods for the efficient and selective synthesis of multi-carbon products. This review first introduces the critical steps involved in forming multi-carbon products. Then, we discuss the reaction conditions that influence the selectivity of C2+ products and explore different catalyst design strategies to enhance the selective production of C2+ products. Finally, we summarize the significant challenges currently facing the eCO2RR field and suggest future research directions to address these challenges.