Atomic Defects\nEngineering Boosts Urea Synthesis toward\nCarbon Dioxide and Nitrate Coelectroreduction

The\natomic defect engineering could feasibly decorate the chemical\nbehaviors of reaction intermediates to regulate catalytic performance.\nHerein, we created oxygen vacancies on the surface of In(OH)<sub>3</sub> nanobelts for efficient urea electrosynthesis. When the oxygen vacancies\nwere constructed on the surface of the In(OH)<sub>3</sub> nanobelts,\nthe faradaic efficiency for urea reached 80.1%, which is 2.9 times\nhigher than that (20.7%) of the pristine In(OH)<sub>3</sub> nanobelts.\nAt −0.8 V versus reversible hydrogen electrode, In(OH)<sub>3</sub> nanobelts with abundant oxygen vacancies exhibited partial\ncurrent density for urea of −18.8 mA cm<sup>–2</sup>. Such a value represents the highest activity for urea electrosynthesis\namong recent reports. Density functional theory calculations suggested\nthat the unsaturated In sites adjacent to oxygen defects helped to\noptimize the adsorbed configurations of key intermediates, promoting\nboth the C–N coupling and the activation of the adsorbed CO<sub>2</sub>NH<sub>2</sub> intermediate. In-situ spectroscopy measurements\nfurther validated the promotional effect of the oxygen vacancies on\nurea electrosynthesis.