Designing bifunctional catalysts for urea electrolysis: progress and perspectives

Abstract

Recently, urea electrolysis has become an attractive method for sustainable energy-saving hydrogen production and simultaneous pollutant degradation. To improve urea electrolysis efficiency and simplify electrolysis systems, developing efficient bifunctional electrocatalysts has attracted great interest. Recently, great achievements have been made in the design of high-performance bifunctional catalysts for urea electrolysis. In this review, the current progress in bifunctional catalysts for urea electrolysis is comprehensively analyzed. The fundamentals and catalyst design principles for urea electrolysis are first discussed. Then, the applications of advanced bifunctional catalysts in urea electrolysis are fully demonstrated, such as single atom catalysts (SACs), metal nanoparticles, alloys, metal (hydr)oxides, chalcogenides, pnictides, metal–organic frameworks (MOFs), and composites. The structure–performance correlation of catalysts as well as their design strategies are emphasized. Current catalysts are also evaluated in terms of their catalytic activities, providing insights into the sensible design of high-performance bifunctional electrocatalysts. Several key perspectives are outlined to guide further studies on practical urea electrolysis-driven sustainable hydrogen production and urea-rich wastewater management.