Monometallic Rh Nanocatalyst Supported on CeO2 Microcuboids for Highly Efficient Dehydrogenation of Hydrous Hydrazine

Abstract

Developing efficient catalysts for hydrogen production from hydrous hydrazine (N2H4•H2O) represents a significant challenge in the field of renewable energy. In this study, a monometallic rhodium nanocatalyst supported on CeO2 microcuboids (Rh/CeO2-MC) was successfully prepared via a one-step wet chemical reduction method. Performance tests demonstrated that the catalyst exhibited excellent activity in the dehydrogenation of N2H4•H2O. Under alkaline conditions at 323 K, the Rh/CeO2-MC catalyst with 5 wt% Rh loading showed the highest activity, achieving 100% hydrogen selectivity-the first reported for a supported monometallic Rh system-along with a turnover frequency (TOF) of 320 h -¹, significantly outperforming most previously reported monometallic catalysts. The enhanced catalytic performance can be attributed to two main factors. First, the alkaline reaction environment plays a key role in promoting the dehydrogenation process. Second, the CeO2-MC support possesses a series of structural advantages, including a high specific surface area (87.29 m 2 /g), abundant oxygen vacancies, and strong metal-support interactions. These features effectively regulate the size and dispersion of Rh nanoparticles and optimize interfacial charge transfer, thereby significantly improving the catalyst's activity and selectivity. Based on the above support-engineering strategy, this study achieved efficient and complete dehydrogenation of both hydrous hydrazine and hydrazine borane (N2H4BH3) in a monometallic system, providing a new approach for the design of high-performance dehydrogenation catalysts.