Effect of support material on the electrocatalytic activity of palladium Nanoparticle toward hydrogen evolution reaction

Support materials are very crucial in noble metal electrocatalyst synthesis. They improve the catalytic activity of the noble metal by increasing their conductivity, surface area, and interactions. This report investigates the effect of support material on palladium nanoparticles' electrochemical activity towards hydrogen evolution reaction. The structural and morphological study was conducted using x-ray diffraction (XRD), Raman Spectroscopy, and Field Emission Scanning Electron Microscope (FE-SEM) that confirmed the support material has a significant effect on the structure of nanocomposite. The hydrogen evolution (HER) performance of the synthesized electrocatalyst was evaluated in 0.5 M H₂SO₄. The Pd-Ni/g-C₃N₄ has higher catalytic activity with a lower overpotential of 55 mV at 10 mA cm² current density and Tafel slope value 56 mV.dec⁻¹ than other support material studied. The overpotential at 10 mA cm² and Tafel slope value for electrocatalyst studied respectively are:- Pd/MoS₂/CB( 78 mV at 10 mA cm² and 57 mV.dec⁻¹), Pd/g-C₃N₄(105 mV at 10 mA cm² and 69 mV.dec⁻¹) and Pd/CB(117 mV at 10 mA cm² and 68 mV.dec⁻¹). The impedance spectroscopy study shows Pd-Ni/g-C3N4 demonstrated the smallest semicircle. Further, the Chronoamparometry(CP) and linear sweep voltammetry (LSV) stability study of the highest performing electrocatalyst demonstrates negligible loss in current density for 12 h and minor change in the polarization curve after10,000 cycles. This study shows how the support material influences noble metal catalysts' activity and stability via the support- metal interactions. (paper)