Hydrogenation of benzaldehyde via electrocatalysis and thermal catalysis on carbon-supported metals

•Benzaldehyde hydrogenates to benzyl alcohol on C-supported metals in aqueous phase.•Intrinsic activity with H2 (TCH) increases as Pt/C < Rh/C ≤ Pd/C; Ni/C is inactive.•All metals are active with cathodic potential (ECH) but H2 evolution occurs.•The selectivity towards hydrogenation increases as Ni/C < Pt/C < Rh/C < Pd/C (95%).•Reaction rates were higher and activation energies were lower in ECH than in TCH.