Surface Modulated Platinum Electrocatalyst via Single Atom Nickel Promoter for Durable Non-aqueous Hydrogen Oxidation

Electrocatalytic hydrogen oxidation reaction (HOR) plays crucial role in various renewable energy conversion processes. Particularly, it offers new opportunities for sustained electrochemical ammonia synthesis when coupled with lithium-mediated nitrogen reduction. But it remains tremendous challenges due to slow reaction kinetics and rapid poisoning of catalysts in non-aqueous electrolyte. Here, we report Ni single atom mediated Pt sites on Ni substrate (PtNi₁/Ni) to boost efficient and durable HOR in organic electrolyte. PtNi₁/Ni exhibits high performance of nearly 100% Faradaic efficiency (FE) and long-term stability over 1000 h in tetrahydrofuran (THF) electrolyte, far beyond commercial Pt electrode (<0.2 h). Theoretical calculations combined with spectroscopic characterizations indicated that Ni single atom contributes to tailoring electronic structure of Pt sites via ligand effects, which effectively reduces the energy barrier of the rate-determining step, and simultaneously as synergistic site in suppressing organic poison species through changing THF adsorption configuration and increasing energy barriers of THF oxidative decomposition. In the lithium-mediated electrochemical ammonia synthesis electrolyzer, it also exhibits good feasibility with high ammonia FE of ∼62%. This work sheds light on the effective strategy of single atom doping for developing active and durable nonaqueous HOR electrocatalyst and presents insightful understanding of anti-poisoning mechanism.