Pd/NiSix: An efficient and stable acid-ORR electrocatalyst

An innovative strategy is proposed to enhance palladium (Pd) catalyst activity and stability performance in proton -exchange membrane fuel cells (PEMFCs). By utilizing a corrosion -resistant NiSix alloy as a support for Pd nanoparticles (NPs), the electronic states of active centers are effectively tuned. Pd/NiSix exhibits a significantly increased half -wave potential for the oxygen reduction reaction (ORR) at 0.857 V vs. reversible hydrogen electrode (RHE), with a 3.2 -fold mass -specific activity and a 1.7 -fold surface -specific activity compared to carbon -supported Pd. Notably, Pd/NiSix demonstrates performance comparable to commercial platinum carbon, including a 12% increase in turnover frequency under PEMFC operating conditions. Density functional theory (DFT) calculations and in situ Raman spectra confirm efficient oxygen adsorption and activation at the NiSix-Pd interface. This approach offers a promising avenue for developing advanced Pd -based electrocatalysts, as an alternative active center, for PEMFCs.