Enhancement of Ampere-Level Current Density of Multicarbon Products by Doping and Stress-Regulated Cu Dual Sites

Optimizing the structure of Cu-based catalysts to achieve efficient electrocatalytic CO2 reduction (CO2RR) into multicarbon (C2+) products is an effective strategy. However, Cu-based catalysts face limitations in the efficient formation of C2+ products due to the increased hydrogen evolution reaction (HER) caused by the imbalance of intermediate reaction rate with the increase of current density. This study employs an in situ derivation strategy to construct dual active sites comprising surface-strained Cu and boron-doped Cu. These sites synergistically facilitate *CO generation and C–C coupling, breaking the current density limit and achieving the efficient conversion of C2+ products. The optimized catalyst achieves a C2+ Faradaic efficiency of 80.5% (ethylene about 50%) at 2.2 A cm–2 and a record-high C2+ production rate of 5.52 mmol h–1 cm–2 at 2.3 A cm–2. In situ spectroscopy and theoretical calculations revealed that the dual sites dynamically balance *CO generation/consumption and accelerate proton-coupled electron transfer, effectively suppressing HER. This work provides insights into the regulation mechanism for CO2-to-C2+ efficient conversion at ampere-level current density.