Hydrogen Evolution Volcano(es) – From Acidic to Neutral and Alkaline Solutions

As the global energy crisis continues, efficient hydrogen production is one of the hottest topics these days. In this sense, establishing catalytic trends for hydrogen production is essential for choosing proper H2 generation technology and catalytic material. Volcano plots for hydrogen evolution in acidic media are well-known, while volcano plot in alkaline media was constructed ten years ago using theoretically calculated hydrogen binding energies. Here we show for the first time that the volcano-type relationships are largely maintained in a wide range of pH values, from acidic to neutral and alkaline solutions, using theoretically calculated hydrogen binding energies on clean metallic surfaces and experimentally measured hydrogen evolution overpotentials. If metallic surfaces are exposed to high anodic potentials, hydrogen evolution can be boosted or significantly impeded, depending on the metal and the electrolyte in which the reaction occurs. Such effects are discussed here and can be used to properly tailor catalytic materials for hydrogen production via different water electrolysis technologies.