Research on the preparation and electrocatalytic hydrogen evolution performance of porous Ni-Cr-Mo-Cu phosphating electrode

Abstract:

In order to solve the low efficiency and high cost of electrode materials used in the process of electrolytic water hydrogen evolution, porous Ni-Cr-Mo-Cu phosphating electrode was prepared by powder metallurgy and low temperature phosphating method. The phase, morphologic structure and element distribution of the electrode were characterized by X-ray diffraction analysis (XRD), field emission electron microscope (SEM) and X-ray energy spectrum analysis (EDS). The electrocatalytic hydrogen evolution properties of phosphor electrode materials were tested by open-circuit potential, linear polarization and ac impedance. The results showed that the porous Ni-Cr-Mo-Cu phosphating electrode exhibited excellent hydrogen evolution performance and its catalytic activity can be improved to a great extent by adjusting the phosphating time. At room temperature, the porous Ni-Cr-Mo-Cu phosphating electrode with a phosphating time of 2 hours has a good hydrogen evolution performance in a solution of 6mol/L KOH, and its hydrogen evolution overpotential is only -0.19V (vs RHE). When the exchange current density is 10 mA/cm2, the corresponding polarization potential is -0.20V (vs RHE). After 18000s, the open-circuit potential (OCP) of the electrode material changed from +0.80 to 0.78V (vs RHE), which decreased only 0.02 V, indicating that the electrode material had good electro-catalytic stability.

Key words:Porous materials; phosphide; preparation; electrocatalysis; hydrogen evolution