Hydrogen evolution reaction

Abstract

This chapter presents a review of electrode materials used for the hydrogen evolution reactions and a comparison of their electrocatalytic activities. The introduction presents a brief definition of various thermodynamic water electrolysis potentials. In general, there are two ways to improve the performance of electrode materials: (1) use of electrode materials characterized by higher intrinsic activity i.e., higher exchange current density and (2) use of electrodes characterized by large real surface area. Both methods are used in practice. In this chapter various electrode materials are reviewed: smooth metals, alloys, intermetallic compounds and composites, Raney type materials (Raney Ni, Zn, etc.), oxides, carbides, sulfides, borides, phosphides, amorphous and nano‐crystalline materials etc., Among the most active materials are noble metals, doped Raney‐type alloys, IrO 2 /Ru 2 O, sulfides, borides, and Ni/Mo based alloys. Unfortunately, noble metals are very expensive and easily poisoned and their activity decreases with time. Although many materials may still be improved and optimized there is a need to study the detailed mechanism and kinetics of the HER on these materials and the relation between the geometric (surface roughness) and intrinsic electrocatalytic properties.

Study of the catalytic activity of 3D macroporous Ni and NiMo cathodes for hydrogen production by alkaline water electrolysis

“…According to the literature of HER on transition metals [10,11,19] and the kinetic parameters obtained (Tafel slopes, b, ranging from 0.113 V dec -1 to 0.137 V dec -1 at 30 ºC, and cathodic transfer coefficient, α c , close to 0.5) we can conclude that the HER on the developed electrocatalysts takes place via the Volmer-Heyrovsky mechanism. Table 3 includes the overpotentials at a fixed current density of -100 mA cm -2 , Another good parameter to assess the catalytic activity is the apparent activation energy (E a ) at equilibrium potential [53].…”

“…Platinum is the electrode material with the highest catalytic activity for HER. However, its high cost and scarcity are the two major barriers for its usage in the industrial water electrolysis, which requires searching for other cheaper and more available materials with good catalytic activity [4,9,10]. Ni-based materials have attracted more and more attention due to their good activity for HER and sufficient corrosion resistance in alkaline solutions at considerable low cost [10][11][12][13].…”

“…However, its high cost and scarcity are the two major barriers for its usage in the industrial water electrolysis, which requires searching for other cheaper and more available materials with good catalytic activity [4,9,10]. Ni-based materials have attracted more and more attention due to their good activity for HER and sufficient corrosion resistance in alkaline solutions at considerable low cost [10][11][12][13]. In order to improve the intrinsic catalytic activity, binary or ternary catalytic systems have been deeply studied such as: NiCo [14][15][16][17][18], NiFe [19][20][21][22], NiW [19,23], NiCu [24], NiAl [25], NiZn [26,27].…”

Hydrogen Oxidation and Evolution Reaction Kinetics on Carbon Supported Pt, Ir, Rh, and Pd Electrocatalysts in Acidic Media

“…Exhaustive reviews of RDE extracted parameters can be found in Refs. [24][25][26][27]. More specifically, on Pt, there was a general agreement that i 0 -values fall into the range of ≈1 mA/cm 2 Pt , [28][29][30] with anodic and cathodic Tafel slopes of 30 mV/decade.…”

Nitrogen‐Doped Graphene with a Three‐Dimensional Architecture Assisted by Carbon Nitride Tetrapods as an Efficient Metal‐Free Electrocatalyst for Hydrogen Evolution

“…While going to higher overpotential, the hydrogen adsorption on the catalyst surface approaches saturation and the initial discharge step becomes the rate determining. [52] The Gibbs free energy for the absorption also depends on the rate determining step. [53,13] If DG H* is positive, the H-adsorption step will be the rate determining step, whereas, a negative value indicates the involvement of the H desorption step as the rate determining step.…”