Hydrogen generation from ammonia electrolysis on bifunctional platinum nanocubes electrocatalysts

•Pt nanocubes (Pt-NCs) with 4.5 nm size are achieved by 2-methylimidazole assisted hydrothermal synthesis.•Pt-NCs display outstanding electroactivity for ammonia oxidation and hydrogen evolution reactions.•A symmetric Pt-NCs||Pt-NCs ammonia electrolyzer based on bifunctional Pt-NCs electrocatalyst is constructed.•The ammonia electrolyzer only requires 0.68 V electrolysis voltage for hydrogen generation.•The ammonia electrolyzer has excellent reversible switch capability for anodic/cathodic reactions.