15 Years of Progress on Transition Metal-Based Electrocatalysts for Microbial Electrochemical Hydrogen Production: From Nanoscale Design to Macroscale Application

• Comprehensive overview of the evolution of transition metal-based catalysts in microbial electrolysis cells from their inception to the present. • Critical design parameters of catalysts evaluated from technical, economic, and sustainability perspectives. • A conceptual framework is proposed to address current challenges and guide future research based on literature best practices. • The potential of artificial intelligence and advanced computational methods in designing high-performance electrodes is highlighted.