Identification of Electrochemically Adsorbed Species via Electrochemical Microcalorimetry: Sulfate Adsorption on Au(111).

ABSTRACT: We investigate compositional changes of an electrochemical interface upon polarization with electrochemical microcalorimetry. From the heat exchanged at a Au(111) electrode upon sulfate adsorption, we determine the reaction entropy of the adsorption process for both neutral and acidic solutions, where the dominant species in solution changes from SO₄ ^2- to HSO₄ ^- . In neutral solution, the reaction entropy is about 40 J mol^-1 K^-1 more positive than that in acidic solution over the complete sulfate adsorption region. This entropy offset is explicable by a deprotonation step of HSO₄ ^- preceding sulfate adsorption in acidic solution, which shows that the adsorbing species is SO₄ * in both soluti

SUBMITTER: Schonig M 

PROVIDER: S-EPMC9542382 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature