Pd-Ni/Cd loaded PPy/Ti composite electrode: Synthesis, characterization, and application for hydrogen storage

Summary A wide compositional range of Pd-Ni/Cd on polypyrrole (PPy)-modified Ti plates (Pd-Ni/Cd/PPy/Ti) was fabricated via electrochemical deposition. The hydrogen absorption properties of the prepared Pd-Ni/Cd/PPy/Ti electrodes were evaluated using cyclic voltammetry and chronoamperometry in acidic media. The optimal Pd 36 -Ni 7 /Cd 57 /PPy/Ti electrode achieved a hydrogen storage capacity of 331.3 mC cm −2 mg −1 and an H/Pd ratio of 0.77. The enhancement of the hydrogen storage was attributed to a synergistic effect between the Pd-Ni/Cd catalysts. The surface morphology, crystallinity, and chemical composition of the Pd-Ni/Cd/PPy/Ti electrode were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), respectively. Hydrogen spillover occurred on the trimetallic catalysts, and secondary hydrogen spillover occurred on the PPy/Ti support. The enhanced hydrogen sorption capacity was due to both the synergistic effect of the trimetallic catalysts and the assistance of PPy, making Pd-Ni/Cd/PPy/Ti a promising hydrogen storage material.