Light-Promoted Hydrazine Dehydrogenation over Ni/NH2-MIL-125: Unraveling Mechanisms for Efficient Hydrogen Production
Jianjun Long1, Caili Hu1, Qilu Yao1
1Key Laboratory of Green Catalysis of Jiangxi Education Institutes, Key Laboratory of Green Hydrogen and Advanced Catalysis of Jiangxi Province, Key Laboratory of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education, College of Chemistry and Materials, Jiangxi Normal University, Nanchang, 330022, China.
Abstract:
Developing efficient, low-cost, and durable catalysts for the complete dehydrogenation of hydrous hydrazine (N2H4·H2O) remains a significant challenge. Herein, a high-performance, visible-light-responsive Ni-loaded amino-functionalized MIL-125 (Ni/NH2-MIL-125) catalyst is fabricated via a facile chemical reduction method, which, for the first time, enables visible-light-enhanced N2H4 dehydrogenation using a non-precious metal catalyst. Under visible light irradiation, Ni/NH2-MIL-125 achieves a turnover frequency (TOF) of 220.2 h-1 at 323 K, more than twice that in the dark (108.1 h-1) and outperforms most reported non-precious metal catalysts. Characterizations and theoretical calculations reveal that the enhanced light-promoted activity arises from light-induced electron transfer from the NH2-MIL-125 to the Ni active sites, which synergistically strengthens N2H4 adsorption and lowers the energy barrier for N─H bond cleavage, the rate-determining step. This work establishes visible-light promotion as a powerful strategy to enhance non-precious metal catalysis and offers a promising avenue for nitrogen-based hydrogen storage systems.
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