Title: Unravelling some factors affecting the electrochemical hydrogen reaction
Time: 2026-04-21 09:00
Lecturer: Prof. Nicolas Alonso-Vante
College of Smart Energy, Shanghai Jiao Tong University
Venue: Room 202, Lu-Jiaxi Building
Abstract：
Hydrogen is considered an ideal source of energy for sustainable development whose combustion with oxygen only provides water as a by-product without carbon dioxide. In addition to the classic hydrogen production processes, electrochemistry, using electricity from renewable energy sources, and photoelectrochemistry constitute an ideal approach for water electrolysis to produce H2.
The process of water electrolysis involves two half-reactions, namely, the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). For practical applications, however, efficient (photo)-electrocatalysts are needed because of the existence of overpotentials (i.e., the difference between the practical potential and the thermodynamic potential). Recent literature reveals that crystalline phase conversion, morphology design and/or doping modulation are strategies that can improve the electrocatalytic properties of nanostructures for the hydrogen evolution reaction in acid and alkaline media. During this reaction the adsorbed (*)-Had and (*)-OHad species interact with additional intermediates (e.g., proton-coupled electron transfer) to generate the product. In addition, the effect coming from the supporting material (local interaction) is, in most cases, underestimated, even under the knowledge that, under certain conditions, the supporting material is active on its own.
Herein, in order to track the effect from the supporting material, selected catalytic nanostructures (based on precious and non-precious centers) supported on surface chemical modified carbon materials (e.g., amorphous carbon, carbon nanotubes and graphite) were generated to anchor chemically and/or photochemically selected catalytic centers. With the support of various physical-chemical characterization techniques, the resulting electrochemical evaluation suggests that, in an acid or alkaline environment, the hydrogen evolution reaction is favored when such electrocatalytic nanostructures interact with the supporting material, observing, e.g., that the HER kinetics proceeds via Volmer-Heyrovsky as the rate determining step of the reaction. Therefore, the combination of high specific surface area, a variety of active sites, and cost-effective nanomaterials is a key research concept.
