Oxygen-deficient SnO2 nanoparticles with ultrathin carbon shell for efficient electrocatalytic N2 reduction

For high-efficiency NH 3 synthesis via ambient-condition electrohydrogenation of inert N 2 , it is pivotal to ingeniously design an active electrocatalyst with multiple features of abundant surfacial deficiency, good conductivity and large surface area. Here, oxygen-deficient SnO 2 nanoparticles encapsulated by ultrathin carbon layer (d-SnO 2 @C) are developed by hydrothermal deposition coupled with annealing process, as promising catalysts for ambient electrocatalytic N 2 reduction. d-SnO 2 @C exhibits high activity and excellent selectivity for electrocatalytic conversion of N 2 to NH 3 in acidic electrolytes, with Faradic efficiency as high as 12.7% at −0.15 V versus the reversible hydrogen electrode (RHE) and large NH 3 yield rate of 16.68 μg h −1 mg cat −1 at −0.25 V vs. RHE in 0.1 mol L −1 HCl. Benefiting from the structural superiority of enhanced charge transfer efficiency and optimized surface states, d-SnO 2 @C also achieves excellent long-term stability.