Programmable Oxygen-Ligand Fields Encode Atomic Cu Coordination for Pathway-Selective CO₂-Nitrate Conversion to Urea.

Abstract

Precise control over the coordination environment of single-atom catalysts remains a central challenge for steering multielectron electrocatalytic reactions. Here, we present oxygen-ligand programming─a chemical strategy that uses tailored surface carbonyl, hydroxyl, and carboxyl groups as programmable ligands to deterministically encode the coordination geometry and electronic configuration of atomic Cu anchored on carbon nanotubes. Atomic layer deposition on these ligand-defined interfaces generates chemically distinct Cu-O-C coordination motifs, whose electronic fingerprints are resolved by X-ray absorption spectroscopy. The programmed ligand fields selectively bias the stabilization of key intermediates: hydroxyl-derived motifs favor the O-bound *CONH species, carboxyl motifs overstabilize *NH_<i>x</i>, while carbonyl-programmed motifs uniquely balance *CO and *NH₂ adsorption, thereby unlocking efficient C-N coupling. This deterministic control over the reaction landscape yields a urea formation rate of 482 mg h^-1 g_cat^-1 and a Faradaic efficiency of 61.2% at -0.6 V. Beyond urea synthesis, oxygen-ligand programming shows a broadly applicable conceptual framework for coordination-tailored single-atom catalysis and molecular pathway design in heterogeneous electrosynthesis.