Direct OC-CHO coupling towards highly C(2+) products selective electroreduction over stable Cu(0)/Cu(2+) interface

Electroreduction of CO(2) to valuable multicarbon (C(2+)) products is a highly attractive way to utilize and divert emitted CO(2). However, a major fraction of C(2+) selectivity is confined to less than 90% by the difficulty of coupling C-C bonds efficiently. Herein, we identify the stable Cu(0)/Cu(2+) interfaces derived from copper phosphate-based (CuPO) electrocatalysts, which can facilitate C(2+) production with a low-energy pathway of OC-CHO coupling verified by in situ spectra studies and theoretical calculations. The CuPO precatalyst shows a high Faradaic efficiency (FE) of 69.7% towards C(2)H(4) in an H-cell, and exhibits a significant FE(C2+) of 90.9% under industrially relevant current density (j = −350 mA cm(−2)) in a flow cell configuration. The stable Cu(0)/Cu(2+) interface breaks new ground for the structural design of electrocatalysts and the construction of synergistic active sites to improve the activity and selectivity of valuable C(2+) products.