A Cell-Wall-Mimetic Bifunctional Interface for Synchronizing CO2 and Nitrite Activation toward Urea Electrosynthesis

Electrochemical urea synthesis from CO2 and nitrite (NO2-) offers a sustainable route for carbon and nitrogen cycling, yet it is hindered by the kinetic imbalance between the sluggish CO2 reduction reaction (CO2RR) and the more facile nitrite reduction reaction (NO2RR). Inspired by the rhizobial cell wall, a natural multifunctional interface that coordinates gas, ion, and molecular transport, we designed a cell-wall-mimetic electrocatalyst featuring a Cu2O/Cu core encapsulated within a pyrrolic-N-containing graphitized porous carbon shell (Cu2O/Cu@C). This bioinspired architecture functions as a nanoregulator to structure a high-density triple-phase interface (gas-liquid-solid interface), manage wettability for concurrent CO2 and electrolyte access, enrich key reactive intermediates, and stabilize the active core. The catalyst achieves a urea yield rate of 50.2 mmol/g/h with a Faradaic efficiency (FE) of 60.6% at -0.6 V, demonstrating that mimicking biological interface principles can effectively harmonize kinetic mismatches in complex cooperative electrocatalysis.