Fig. 2: Simulation and experiment studies.

A From left to right are the K+ concentration distribution over surface of solid sphere, hollow sphere with channels, and within channels of hollow sphere at −700 mA. B From left to right are the distribution of K+ concentration over surface of solid sphere, hollow sphere, and within channels of hollow sphere at −900 mA. C K 2p XPS spectra of La-Cu HS and La-Cu SS after CO2RR testing in 0.05 M H2SO4 containing 3 M KCl electrolyte. D From left to right are the pH distribution in electrolyte near surface of solid sphere, hollow sphere, and within channels of hollow sphere at −700 mA. E From left to right are the pH distribution in electrolyte near surface of solid sphere, hollow sphere, and within channels of hollow sphere at −900 mA. In-situ SERS spectra of (F) La-Cu HS and (G) La-Cu SS under different current densities in 0.05 M H2SO4 containing 3 M KCl electrolyte.