Modification and hydrogen evolution characteristics of post-processing PtCu/C alloy solid solubility gradient membrane catalyst

PtCu/C membrane catalysts were prepared by ion beam sputtering (IBS) with moving bimetallic Pt and Cu targets. The surface structure of the catalyst with large specific surface area was obtained by surface etching of the gradient membrane with 1mol/L HNO3. The results of X-ray diffraction (XRD) analysis show that the PtCu replacement solid solution alloy is formed on the surface of the composite membrane electrode, the original Pt lattice is contracted and the spacing between the crystal planes is narrowed. Atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM) RTEM-STEM measurements show that the surface of the post-processed samples has multi-peak structure and trench-pore structure. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were used to test the electrochemical hydrogen evolution performance of the samples. The results show that the dealloying of gradient materials can effectively reduce the platinum loading and improve the exchange current density of electrochemical hydrogen evolution. The Pt loading of the post-treatment sample is decreased by 20.29%, the exchange current density of electrochemical hydrogen evolution reaches 0.004217A/cm2, and the catalytic performance is improved by 20.58%.