Constructing Ru single-atomic sites through potential-induced self-reconstruction to accelerate electrocatalytic nitrate reduction for ammonia production

Conversion of NO 3 − -to-NH 3 via the electrocatalytic nitrate reduction reaction (NO 3 - RR) is an emerging strategy for ammonia production and storage of “green hydrogen”, but is limited by the dissatisfactory activity and selectivity. In this study, we discovered that cobalt carbonate hydroxide (Co 2 (OH) 2 CO 3 ) underwent a potential-induced self-reconstruction to cobalt hydroxide (Co(OH) 2 ) during NO 3 - RR. The incorporation of Ru into Co 2 (OH) 2 CO 3 expedited the aforementioned self-reconstruction process and resulted in the formation of Ru single-atomic sites (Ru SASs) anchored on Co(OH) 2 nanosheets. This structure is reported as a highly efficient electrocatalyst for NO 3 − -to-NH 3 conversion and exhibits exceptional electrochemical performance in zinc-NO 3 − batteries. Theoretical analysis revealed that the conversion of NO 3 − -to-NH 3 occurred on Ru SASs through an N-end pathway with *NO as a characteristic intermediate. Furthermore, Ru SASs facilitated the thermodynamic-determining step of *NH 2 -to-*NH 3 , thus promoting the overall NO 3 − -to-NH 3 conversion process.