Is Platinum a Proton Blocking Catalyst?

Fuente: arXiv
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Main Authors: Saksena, Aparna, Zhao, Yujun, Prabhakar, J. Manoj, Raabe, Dierk, Gault, Baptiste, Joshi, Yug
Format: Preprint
Published: 2025
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author Saksena, Aparna
Zhao, Yujun
Prabhakar, J. Manoj
Raabe, Dierk
Gault, Baptiste
Joshi, Yug
author_facet Saksena, Aparna
Zhao, Yujun
Prabhakar, J. Manoj
Raabe, Dierk
Gault, Baptiste
Joshi, Yug
contents Platinum, to date, is the most widely applied electrocatalyst for hydrogen evolution reaction (HER) in acidic media. It is assumed to be a proton-blocking catalyst with only surface-limited adsorption of the reaction intermediates. Here, we critically evaluate the bulk interaction of Pt with hydrogen (H), and its heavier isotope deuterium (D), by monitoring operando mass change of the Pt electrode during galvanostatic heavy/water splitting by employing an electrochemical quartz crystal microbalance. Unexpectedly, we observe an irreversible temporal mass gain and a change in the reaction's overpotential, arising from diffusion of H/D into Pt, confirmed by atom probe tomography and thermal desorption spectroscopy. Sub-surface concentration of at least ca. 15 at. % of D in Pt was observed, diffusing down to a depth of more than 10 nm. Analytical description quantified the diffusion coefficient of D in Pt to be 3.2X10^-18 cm2Xs-1. These findings challenge the existing credence of Pt-proton interaction being limited to the surface, prompting the expansion of the catalyst design strategies to account for property-modifying bulk diffusion of H/D in the Pt matrix
format Preprint
id arxiv_https___arxiv_org_abs_2510_09522
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Is Platinum a Proton Blocking Catalyst?
Saksena, Aparna
Zhao, Yujun
Prabhakar, J. Manoj
Raabe, Dierk
Gault, Baptiste
Joshi, Yug
Chemical Physics
Materials Science
Platinum, to date, is the most widely applied electrocatalyst for hydrogen evolution reaction (HER) in acidic media. It is assumed to be a proton-blocking catalyst with only surface-limited adsorption of the reaction intermediates. Here, we critically evaluate the bulk interaction of Pt with hydrogen (H), and its heavier isotope deuterium (D), by monitoring operando mass change of the Pt electrode during galvanostatic heavy/water splitting by employing an electrochemical quartz crystal microbalance. Unexpectedly, we observe an irreversible temporal mass gain and a change in the reaction's overpotential, arising from diffusion of H/D into Pt, confirmed by atom probe tomography and thermal desorption spectroscopy. Sub-surface concentration of at least ca. 15 at. % of D in Pt was observed, diffusing down to a depth of more than 10 nm. Analytical description quantified the diffusion coefficient of D in Pt to be 3.2X10^-18 cm2Xs-1. These findings challenge the existing credence of Pt-proton interaction being limited to the surface, prompting the expansion of the catalyst design strategies to account for property-modifying bulk diffusion of H/D in the Pt matrix
title Is Platinum a Proton Blocking Catalyst?
topic Chemical Physics
Materials Science
url https://arxiv.org/abs/2510.09522