Formation of C–C bonds during electrocatalytic CO2 reduction on non-copper electrodes

The formation of C–C bonds between the carbonaceous intermediates generated during the electrocatalytic CO2 reduction reaction (CO2RR) is the key in producing high-value multi-carbon products. At present, Cu-based electrocatalysts are the most promising for this purpose. However, critical challenges concerning their selectivity, stability and energy efficiency remain. Recently, some non-Cu-based electrocatalysts have been reported to exhibit excellent multi-carbon product selectivity at low overpotentials, and some are even able to produce multi-carbon molecules that were not detected on Cu-based electrodes. This sets a new direction in which novel non-Cu electrocatalysts could be explored. These recent advances are summarized in this review. We focus on the CO2RR to multi-carbon products on non-Cu electrodes in aqueous electrolytes under ambient conditions, with an emphasis on the C–C bond formation mechanisms. The current challenges and corresponding strategies for the CO2RR to multi-carbon products on non-Cu catalysts are also discussed.