(528f) The Role of Hydrogen Intercalation in the Kinetics of Hydrogen Evolution on WO3
AIChE Annual Meeting
Wednesday, November 10, 2021 - 4:45pm to 5:00pm
In this work, we tested this hypothesis and found that bulk hydrogen intercalation in WO3 induces significant changes in hydrogen surface adsorption, and therefore HER catalysis. First, we used UV-vis spectroscopy and density functional theory (DFT) to confirm the semiconductor-metal transition in WO3 that results from hydrogen intercalation. We then used constant-potential DFT to determine the activation barriers of Langmuir-Hinshelwood (Volmer-Tafel) and Eley-Rideal (Volmer-Heyrovsky) mechanisms at various stoichiometries of HxWO3. We used these constant-potential barriers to construct first-principles current-potential relationships that were directly compared to experimental cyclic voltammograms collected on a rotating disk electrode. The computational results showed that intercalation proceeds as a bulk diffusion-limited process, in agreement with experiment. Our comparisons also showed that non-intercalated WO3 cannot be responsible for experimentally observed HER current densities. The experimental results are reproduced from first-principles by considering bulk WO3 hydrogen intercalation.