Mechanistic Study of Electrocatalytic Dehydrogenation Steps using the Rotating Ring-Disk Electrode

• Grant number: 25/09372-5
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2025
• End date: June 30, 2029
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Hamilton Brandão Varela de Albuquerque
• Grantee: Pedro Lobo Hermes Lima
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 19/22183-6 - Electrocatalysis VI: fundamental and applied aspects of emerging and classical problems in electrochemical energy conversion, AP.TEM

Abstract

In the context of global decarbonization, methanol, ethanol, and glycerol stand out as key molecules for energy conversion between chemical and electrical forms, whether in fuel cells or electrochemical reforming for clean hydrogen gas production and high-value-added chemical byproducts. However, their oxidation mechanisms (AOR) still present gaps, with unknown and controversial steps, due to the complexity of reaction pathways and competitive intermediate formation. This project aims to elucidate these mechanisms through in situ investigation of dehydrogenation steps, employing a standard configuration rotating ring-disk electrode (RRDE) (Pt-Pt) system to achieve protonated species selectivity - with potential surface modifications to: (1) optimize disk catalysis and (2) enhance H+ detection at the ring. The study will use alkaline electrolytes (NaOH, pH 11-14) to evaluate the effect of OH- ions on dehydrogenation kinetics, while also investigating temperature influence (10-50°C and alcohol boiling points). Analyses combine traditional potentiodynamic techniques with simultaneous current measurements (disk/ring), validated by HPLC and DEMS. To deepen and refine mechanistic understanding, non-stationary regime experiments will be conducted, correlating disk oscillations with ring current peaks. This integrated approach will enable mapping of dehydrogenation steps, contributing to the development of more efficient and sustainable electrochemical processes for biomass valorization.