Core@shell structured Au@SnO nanoparticles with improved N adsorption/activation and electrical conductivity for efficient N fixation.

The design of electrocatalysts with enhanced adsorption and activation of nitrogen (N) is critical for boosting the electrochemical N reduction (ENR). Herein, we developed an efficient strategy to facilitate N adsorption and activation for N electroreduction into ammonia (NH) by vacancy engineering of core@shell structured Au@SnO nanoparticles (NPs). We found that the ultrathin amorphous SnO shell with enriched oxygen vacancies was conducive to adsorb N as well as promoted the N activation, meanwhile the metallic Au core ensured the good electrical conductivity for accelerating electrons transport during the electrochemical N reduction reaction, synergistically boosting the N electroreduction catalysis. As confirmed by the N-labeling and controlled experiments, the core@shell Au@amorphous SnO NPs with abundant oxygen vacancies show the best performance for N electroreduction with the NH yield rate of 21.9 μg h mg and faradaic efficiency of 15.2% at -0.2 V, which surpass the Au@crystalline SnO NPs, individual Au NPs and all reported Au-based catalysts for ENR.