Electronic Effect or Underpotentially Deposited Hydrogen? Insights into the effect of Pb on formic acid electro-oxidation on Pt

Roychowdhury, D and Veenu, Veenu and Ranjan, C (2022) Electronic Effect or Underpotentially Deposited Hydrogen? Insights into the effect of Pb on formic acid electro-oxidation on Pt. In: ChemCatChem .

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Abstract

Formic acid is a promising energy carrier. Electrochemical formic acid oxidation can serve as an important reaction within fuel cells. Although Pt remains the best-known catalyst, surface adatoms like Pb have been known to promote formic acid electro-oxidation significantly. We have carried out first principle-based calculations, bonding analysis, and experiments to provide insights for this enhancement. Results show that upon adsorption of Pb on the Pt surface, an upshift of Pt energy levels above the Fermi energy is observed, which in general influences the binding energy of the adsorbates. Reaction free energy vs. electrochemical potential diagrams were constructed to understand the interaction of formic acid and water with Pt and Pb-modified Pt surfaces. Electrochemical experiments indicating the underpotentially deposited hydrogen (Hupd) region and potential-dependent apparent activation energies indicate that Hupd suppression has an important role to play in the formic acid oxidation reaction. The suppression of the Hupd region on Pb-modified Pt surface results in free Pt sites that can carry out direct formic acid oxidation to CO2. © 2022 Wiley-VCH GmbH.

Item Type:	Journal Article
Publication:	ChemCatChem
Publisher:	John Wiley and Sons Inc
Additional Information:	The copyright for this article belongs to John Wiley and Sons Inc
Keywords:	Activation energy; Adatoms; Binding energy; Electrooxidation; Free energy; Fuel cells; Gas adsorption; Hydrogen; Platinum, Electrochemicals; Electronic effects; Energy carriers; Formic acid electrooxidation; Formic acid oxidation; Hydrogen adsorption; Hydrogen adsorption region; Pb adatom; Platinum catalyse; Under-potentially deposited hydrogen, Formic acid
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	19 May 2022 05:47
Last Modified:	19 May 2022 05:47
URI:	https://eprints.iisc.ac.in/id/eprint/72007

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