Current Progress in Layered Double Hydroxide-Based Electrocatalyst for Urea Oxidation: Insights into Strategies and Mechanisms

Abstract

Urea oxidation reaction (UOR) presents a more favorable alternative to the conventional oxygen evolution reaction (OER) for hydrogen production due to its lower thermodynamic potential. These methods offer advantages over traditional hydrogen production approaches due to favorable operating conditions and potentially lower costs. However, the complex 6-electron transfer process in UOR limits its performance. Researchers are tackling this challenge by designing advanced electrocatalysts with optimized properties like porosity, heterostructures, controlled defects, surface functionalization, and fine-tuned electronic structures. This significant progress in UOR catalyst design holds promise for the future of clean energy technologies. In view of this, LDHs (Layered double hydroxide) are attracting significant interest for their potential role in urea electrolysis due to their synergistic cooperation of metals, flexible configuration, tunable electronic composition and unique layered structure. This review examines the significant advancements of LDHs recently achieved in the design and synthesis of UOR catalysts. Beyond highlighting the recent breakthroughs in UOR catalyst, this review critically stresses the designing strategies and challenges in urea electrolysis towards energy conversion. Moreover, this comprehensive approach provides a valuable forward-looking perspective on future research directions.