Selective Urea Electrosynthesis from CO₂ and Nitrate on Spin‐Polarized Atomically Ordered PdCuCo

Abstract

The electrocatalytic conversion of NO₃ ^- and CO₂ into urea features a potential means of reducing carbon footprint and generating value-added chemicals. Nonetheless, due to the limited efficiency of carbon-nitrogen (C─N) coupling and the competing side reaction that forms ammonia, the urea selectivity and production yield have remained low. In this work, a spin-polarized cobalt-doped, atomically ordered PdCu intermetallic compound (denoted as PdCuCo) is developed as an efficient urea electrosynthesis catalyst. The Pd and Cu serve as the adsorption sites for CO₂ and NO₃ ^-, respectively, and the spin-polarized Co sites promote the adsorption of *NO intermediate, followed by hydrogenation of *NO at its N-terminal to form *HNO, instead of at its O-terminal. The difference in the hydrogenation position switches the subsequent reaction pathway to produce urea, in contrast to the PdCu or Ni-doped PdCu intermetallic compounds with main product selectivity of ammonia. The PdCuCo electrocatalyst exhibited an outstanding electrosynthesis of urea from NO₃ ^- and CO₂, including a Faradaic efficiency of 81%, a high urea yield of 227 mmol g_cat. ^-1 h^-1, and a notable electrochemical stability of >260 h, suggesting the attractive potential of designing spin-polarized catalytic sites for carbon-nitrogen coupling processes.