CO2 electrolysis to multi-carbon products in strong acid at ampere-current levels on La-Cu spheres with channels

Achieving satisfactory multi-carbon (C₂₊) products selectivity and current density under acidic condition is a key issue for practical application of electrochemical CO₂ reduction reaction (CO₂RR), but is challenging. Herein, we demonstrate that combining microenvironment modulation by porous channel structure and intrinsic catalytic activity enhancement via doping effect could promote efficient CO₂RR toward C₂₊ products in acidic electrolyte (pH ≤ 1). The La-doped Cu hollow sphere with channels exhibits a C₂₊ products Faradaic efficiency (FE) of 86.2% with a partial current density of -775.8 mA cm^-2. CO₂ single-pass conversion efficiency for C₂₊ products can reach 52.8% at -900 mA cm^-2. Moreover, the catalyst still maintains a high C₂₊ FE of 81.3% at -1 A cm^-2. The channel structure plays a crucial role in accumulating K⁺ and OH^- species near the catalyst surface and within the channels, which effectively suppresses the undesired hydrogen evolution and promotes C-C coupling. Additionally, the La doping enhances the generation of *CO intermediate, and also facilitates C₂₊ products formation.