Positive feedback of intermediates promotes efficient electrocatalytic C-N coupling at AuPd/SnOx interfaces

Efficient electrocatalytic co-reduction of CO 2 and NO 3 − to urea involves simultaneous generation and stabilization of C- and N-coupling intermediates. Herein, we report positive feedback at the interfaces of an AuPd/SnO x catalyst that enables generation and stable co-adsorption of *CO and *NH 2 OH at low-potential, fostering efficient C-N coupling for urea formation. A combination of in-situ spectroscopic analyses and theoretical calculations show that *CO 2 captures electrons by bonding to the AuPd/SnO x interface, leading to positively charged Pd sites, which promote the NO 3 RR to give the key N-intermediate *NH 2 OH. The adsorbed *NH 2 OH provides electron feedback to the catalyst surface , which not only enhances the adsorption of CO 2 and promotes the conversion of *CO 2 to *CO to accelerate the CO 2 RR, but also enhances the adsorption strength of the catalyst for *CO. Owing to this positive feedback, the Faraday efficiency and yield of urea reached 21.3 % and 1280.5 μg∙h −1 ∙mg −1 at −0.2 V (versus the relative hydrogen electrode), surpassing the performance of most previously reported catalysts. This finding provides new insights into catalyst design for advancing C-N coupling systems.