Hydrogen Evolution and Oxygen Reduction Reactions in Acidic Media Catalyzed by Pd₄ S Decorated N/S Doped Carbon...

The template-free synthesis and the characterization of an active electrocatalyst are performed for both the hydrogen evolution and oxygen reduction reactions in acidic media. In this work, the unique chelation mode of benzene-1,4-dithiocarboxamide (BDCA) is first used to synthesize a novel palladium-BDCA coordination polymer (PdBDCA) as a precursor of palladium sulfide nanoparticles-decorated nitrogen and sulfur doped carbon (Pd₄ S-SNC). The newly synthesized PdBDCA and Pd₄ S-SNC nanoparticles are characterized using chemical, electrochemical, and surface analysis methods. Notably, the nanoparticles obtained at 700 °C exhibit the remarkable catalytic property for the hydrogen evolution reaction in 0.5 m H₂ SO₄ , showing the overpotential of 32 mV (vs reversible hydrogen electrode (RHE)) and Tafel slope of 52 mV dec^-1 , which are comparable to that of Pt/C. The catalyst also shows a high oxygen reduction activity, offering the half-wave and onset potentials of 0.92 and 0.77 V (vs RHE) in 0.5 m H₂ SO₄ , with improved methanol tolerance and long-term stability compared with Pt/C. The present study gives a way for the design of excellent electrocatalyst for the energy conversion devices in the corrosive acidic environment.