Isotope-dependent Tafel analysis probes proton transfer kinetics during electrocatalytic water splitting
Year: 2025
Type: article
Abstract: Proton transfer plays an important role in both hydrogen and oxygen evolution reactions during electrocatalytic water splitting to produce green hydrogen. However, directly adapting the conventional proton/deuterium kinetic isotope effect to study proton transfer in heterogeneous electrocatalytic processes is challenging. Here we propose using the shift in the Tafel slope between protic and deuteric electrolytes, or the Tafel slope isotope effect, as an effective probe of proton transfer characteristics. Comparison of the Tafel slope isotope effect for diverse hydrogen and oxygen evolution reaction electrocatalysts in different pH environments reveals that proton transfer is both pH and structure dependent. Using ruthenium oxide as an example, we show that local structure modification can change the rate-determining step from an electrochemical, concerted proton–electron transfer step to a chemical step and improve the oxygen evolution activity in acid. The isotope-dependent Tafel analysis will facilitate a better understanding of the proton transfer behaviours during electrocatalytic processes and provide guidance for designing efficient electrocatalysts. Proton transfer plays a key role in fuel-producing reactions, but directly monitoring these processes in heterogeneous electrocatalysts is challenging. Now it has been shown that shifts in the Tafel slope in protic versus deuteric electrolytes can elucidate the rate-determining step during water splitting and reveal pH- and structure-dependent proton transfer behaviours.
Source: Nature Chemistry
Institutions: University of Wisconsin–Madison, Harbin Institute of Technology, Paul Scherrer Institute, Fudan University, Nanjing Normal University, Nantong University, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, Chinese Academy of Sciences, Institute of Physics, Zhejiang University
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $12,690
Funders: National Science Foundation, U.S. Department of Energy, Natural Science Foundation of Shanghai, National Natural Science Foundation of China, China Scholarship Council, Office of Science, National Science Fund for Distinguished Young Scholars, Division of Materials Research, Division of Chemistry, Argonne National Laboratory
Awards: G102163711, G107546177, G1124784177, G1313983767, G140356544, G1664757510, G187035202, Wisconsin MRSEC, G2287611682, G262962599, G3075337988, G3350484252, G3589692066, G4031499446, G498139845, G513797252, G6092972593, G6420496198, G6848031779, G6918803902, G8485887974, CAS: Design and Mechanistic Understanding of Emerging Metal Chalcogenide Electrocatalysts for Selective Two-Electron Oxygen Reduction, 新型同质异质结电催化剂的可控合成与性质研究, G880751848, G969889393, G993149817
OpenAlex ID: W4414083407