镍-碳化钨氢催化阴极表面积与活性

STUDY ON THE ACTIVITY AND ACTIVE SURFACE OF THE HYDROGEN ELECTRODE OF Ni-WC SYSTEM

本文对氯碱工业离子膜电解槽的镍网阴极基底进行电复合镀Ni-WC,考察了电极有效面积与电极对氢析出的催化活性间的关系,分析了随着电极有效表面积增大,电极上析氢反应机理的变化.当镀层荷载量达到一定程度时,电极的催化活性可达Pt、Pd等贵金属电极的水平.

The electrocatalytic electrode for hydrogen evolution was prepared by electroplating Ni-WC composite on the substrate of Ni net and used in chloralkline industry as a cathode. The coated electrode had a porous shape and its active surface area was several or tens times larger than its apparent surface area. The relationship between the catalytic activity of the coated electrode and the active surface was investigated. Obviously, the electrode with such a large surface area was benificial to lower the overpotential of hydrogen evolution. The electrochemical parameters indicate that the hydrogen evolution process on the electrode is diffusion controlled and the catalytic activity and stability of the Ni-WC composite coated electrode was as good as Pt or Pd. The mechanism of hydrogen evolution tended to change with the increase of the active surface, which made the Ni-WC system coated electrode have more advantages in the condition of larger electric density over the uncoated electrode.