Correlating the hydrogen evolution reaction activity in alkaline electrolytes with the hydrogen binding energy on monometallic surfaces

Abstract

The slow reaction kinetics of the hydrogen evolution and oxidation reactions (HER/HOR) on platinum in alkaline electrolytes hinders the development of alkaline electrolysers, solar hydrogen cells and alkaline fuel cells. A fundamental understanding of the exchange current density of the HER/HOR in alkaline media is critical for the search and design of highly active electrocatalysts. By studying the HER on a series of monometallic surfaces, we demonstrate that the HER exchange current density in alkaline solutions can be correlated with the calculated hydrogen binding energy (HBE) on the metal surfaces via a volcano type of relationship. The HER activity varies by several orders of magnitude from Pt at the peak of the plot to W and Au located on the bottom of each side of the plot, similar to the observation in acids. Such a correlation suggests that the HBE can be used as a descriptor for identifying electrocatalysts for HER/HOR in alkaline media, and that the HER exchange current density can be tuned by modifying the surface chemical properties.

Electrocatalysts for hydrogen oxidation and evolution reactions

“…Yan and co-authors [30] demonstrated that the hydrogen binding energy can also be used as a descriptor for the HER activity measured in base, where a similar volcano shaped plot was also obtained (Fig. 3c).…”

Size-Dependent Hydrogen Oxidation and Evolution Activities on Supported Palladium Nanoparticles in Acid and Base

“…The lower limit was chosen to be 0.07 V to avoid the diffusion of H atom into the Pd lattice. 11 In 0.1 M KOH, the underpotential deposited hydrogen (H upd ) adsorption and desorption peaks in the potential region of 0.07-0.45 V are very asymmetric and the double layer regions are not well defined (Figure 3a), making it difficult to determine sur- face areas using the H upd adsorption and desorption peaks. Additionally, the H upd desorption peaks for all the samples in 0.1 M KOH are located at around 0.35 V (Figure 3a).…”

“…Pd and Pd-based catalysts have been studied as HOR catalysts in fuel cells, 9,10 and lower HOR/HER activities were observed on Pd/C than bulk Pd, [11][12][13] suggesting a particle size effect. However, a fundamental understanding of HOR/HER kinetics on Pd and a systematic study of the particle size effect are largely missing.…”

A selective and efficient electrocatalyst for carbon dioxide reduction

“…By comparing the amount of electrons passed during the oxidation process, the relative surface areas between different Ag electrodes can be obtained (Supplementary Fig. 8) 33,39 .…”