Year: 2026
Type: preprint
Abstract: Electrochemical conversion of methane into liquid oxygenates has attracted significant attention as a sustainable process for the valorization of natural gas. Platinum single crystals provide well-defined model surfaces for mechanistic studies of methane oxidation via direct activation, with Pt(100) being the only facet capable of catalyzing this reaction. Here, we combine electrochemical measurements and theoretical calculations to investigate how the microenvironment at the Pt(100) electrode interface influences methane activation. We first confirm the crucial role of (100) terraces as the main active sites by using electrodes with different degrees of surface order, obtained by cooling them under different atmospheres. Cyclic voltammetry further reveals that methane dissolved in the electrolyte can be activated only at potentials between 0.30–0.60 V vs RHE, a window in which OH species are co-adsorbed on the electrode surface in acidic media. In contrast, more alkaline electrolytes inhibit the overall reaction. Density functional theory calculations show that interfacial OH directs methane activation toward either OH-mediated or surface-mediated C–H abstraction, with activation barriers of 1.0 and 0.6 eV, respectively. By accounting for the co-presence of adsorbed OH during methane activation, our results provide a more realistic description of the electrochemical interface and rationalize the pronounced structure sensitivity of methane activation on platinum surfaces.
Source: ChemRxiv
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: green
Funders: Ministerio de Ciencia, Innovación y Universidades, Centres de Recerca de Catalunya, Institut Català de Nanociència i Nanotecnologia, European Commission, Generalitat de Catalunya, Generalitat Valenciana, Universitat de Barcelona, Universitat Autònoma de Barcelona, Alliance de recherche numérique du Canada, Natural Sciences and Engineering Research Council of Canada, European Regional Development Fund, Agencia Estatal de Investigación
Awards: G1119546765, G1206670709, G1422035950, Computational Catalysis for Clean Energy Transformation, G2262748287, G3005324705, G3480869486, G354764522, G4042783231, G418495324, G4212894969, G4228227490, G4866112958, G4998900716, G5080475149, G5635532810, G5706383408, G5967599077, G6033112984, G6605876378, G6656126374, G6762955466, G7084143925, G7395345766, G7805626310, G811039158, G8497050386, G8667377315
OpenAlex ID: W7204946459