Ordered Cu─Pd Intermetallic Alloy With Complementary Facets Enables Efficient Urea Electrosynthesis via Accelerated C─N

ABSTRACT

CO ₂ and nitrate are widespread contaminants. Co‐electrolysis of them to produce urea enables eco‐friendly pollution treatment and agricultural support, while bare Cu suffers low selectivity, quick deactivation and dominant hydrogen evolution reaction competition. Herein, we synthesize long‐range ordered concave CuPd intermetallics (f‐CuPd) by liquid reduction and gradient annealing. Characterizations confirm annealing converts disordered face‐centered cubic d‐CuPd to ordered body‐centered cubic phase. Fully ordered f‐CuPd exposes complementary (211) and (001) facets with evenly mixed Cu and Pd without segregation. Its ordered atomic arrangement induces Pd to Cu charge transfer and restrains Cu surface oxidation. Electrochemical measurements reveal exceptional electrocatalytic activity toward urea synthesis, attaining a urea production rate of 74.78 mmol h ⁻¹ g _cat ⁻¹ and steady catalytic activity throughout 28 h of uninterrupted electrolysis. In situ spectra track the reaction and prove the ordered structure adjusts interfacial water to generate active hydrogen and avoid competitive adsorption of CO ₂ and nitrate intermediates. Density functional theory calculations uncover a unique synergistic effect between two crystal facets. The (211) facet drives efficient CO ₂ activation to form ^* CO intermediates, while the adjacent (001) facet facilitates nitrate reduction and C─N coupling with substantially reduced kinetic barriers. Reaction intermediates migrate across distinct crystal facets, driving highly efficient urea formation.