A review on the performance of heterogeneous electrocatalysts in the electrochemical evolution of hydrogen

Hydrogen gas has a high energy density and if it is produced with electricity from clean energies, it is considered a clean and economical fuel. Hydrogen production is done by electrochemical separation of water. This leads us to investigate cheap and resistant electrodes that require a lower voltage for the electrochemical production of hydrogen. In this study, we focused more on the electrocatalytic activity of homogeneous electrocatalysts without noble metals. The electrochemical production of hydrogen depends on the surface and intrinsic characteristics of the electrode, which in the studies have been investigated by selecting the desired elements and compounds such as noble metals, strain engineering, doping heteroatoms, coupling, designing synergistic composites, and nanomaterials engineering including layer thinning, edge engineering, defects and mesopores improved them. The criteria for choosing the best electrode were high electrocatalytic activity, stability, cheapness, safety and abundance. To measure the electrocatalytic activities, the value of the Tafel slope, the onset potential and the overpotential against the current density were used. The investigated electrodes mostly included Fe, C, O, S, Al, Mo, Se, Ti, Co, Ni, V, Cu, Ta, and a few had Pt, Ir, Ru.

Keywords:

Hydrogen production , Homogeneous Electrocatalysts , Hydrogen Evolution , HER , Electrode