Benefits and challenges of methanol and ammonia electro-oxidation in AEM electrolysis: An experimental parametric comparison of catalysts and feedstocks

This study investigates the applicability of catalysts commonly used in anion-exchange membrane (AEM) water electrolysis for biomass electro-oxidation. In this work, conventional AEM water electrolysis was compared with the electro-oxidation of biomass derivatives, specifically methanol and ammonia, under identical operating conditions. A comprehensive electrochemical analysis was performed using various catalysts, including Pt/C, PtRu/C, and Ni/C. The results demonstrate that biomass electro-oxidation leads to a consistent reduction in operating potential, while maintaining the same hydrogen production rate. Notably, this study provides a direct and systematic comparison of multiple catalysts and biomass substrates within the same experimental framework, which remains underexplored in current literature. The results indicate that ammonia induces the largest decrease in operating potential for Ni-based catalysts – 0.25 V, whereas methanol produces a similar effect for Pt-based catalysts – 0.23 V. Furthermore, 20 h stability tests confirmed the stable performance of the investigated catalysts during biomass electro-oxidation in AEM electrolysis systems.