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.