Recent progress of two-dimensional metal-base catalysts in urea oxidation reaction

Urea oxidation reaction (UOR) is an auxiliary water electrolysis hydrogen production technology developed in recent years to replace oxygen evolution reaction and reduce energy consumption, which can produce hydrogen more efficiently by low theoretical potential, reduce the average cost of electrochemical hydrogen production, and is a frontier research hotspot for renewable hydrogen energy. Two-dimensional (2D) nanomaterials as electrocatalysts have many favorable potential, such as it can effectively reduce the resistivity of materials and increase the specific surface area with certainty. This paper reviews the application of 2D materials in UOR in alkaline electrolytes. And a cross-sectional comparison of various material performance data including overpotential, Tafel slope, electrochemical active surface area (ECSA) and i-t stability test was conducted, which could illustrate the differences between materials composed of different elements. In addition, the main challenges hindering the progress of research on 2D materials in urea electrocatalysis processes and promising materials in this field in future are summarized and prospected. It is believed that this review will contribute to designing and analyzing high-performance 2D urea electrocatalysts for water splitting.