Tuning the electrocatalytic activity of Pt by structurally ordered PdFe/C for the hydrogen oxidation reaction in alkaline media†
Tuning the hydrogen adsorption energy (EH) by controlling the surface electronic structure of Pt is essential for enhancing the hydrogen oxidation reaction (HOR) performance in alkaline media. This could be achieved by forming a Pt skin on PdFe/C nanoparticles with structurally ordered intermetallic (O-PdFe@Pt/C) or disordered alloy (D-PdFe@Pt/C). The HOR activity on O-PdFe@Pt/C exhibits an exchange current density of 1.49 A mgPt−1, which is 3.87 and 7.56 times higher than that on D-PdFe@Pt/C (0.385 A mgPt−1) and Pt/C (0.197 A mgPt−1), respectively. The excellent electrocatalytic HOR performance on O-PdFe@Pt/C can be ascribed to the attenuation of EH on the Pt shell induced by the structurally ordered PdFe core, where the EH on O-PdFe@Pt surface is 0.18 eV smaller than that on Pt according to DFT calculations.