Anatase-Type TiO2-Modified Amorphous NiMo Nanoparticles with Superior Catalytic Performance toward Dehydrogenation of Hydrous Hydrazine

A safe, efficient, and responsive online hydrogen source is critical for the commercial application of proton exchange membrane fuel cells (PEMFCs). Catalysts play an important role in accelerating the development of hydrous hydrazine as a promising online hydrogen source, and the development of hydrous hydrazine (N2H4middot H2O) as a promising online hydrogen source for PEMFCs requires superior catalysts with low cost and high activity. Herein, we report the synthesis of a supported amorphous catalyst NiMo/TiO2 using a combination of impregnation and coreduction methods. The NiMo/TiO2 catalyst can be responsive and completely decompose hydrous hydrazine to produce hydrogen in 1.5 min with a H2 selectivity of 100% and a turnover frequency (TOF) value of 484 h-1 under alkaline conditions at 343 K, outperforming most non-noble metal catalysts. Moreover, H2 selectivity has no decline after 10 cycles. The excellent catalytic properties can be attributed to the strong synergistic interaction between the support TiO2 and NiMo nanoparticles, as well as the amorphous NiMo nanoparticles possessing a high concentration of coordinated unsaturated sites. In addition, the doping of Mo leads to the modification of the electronic and geometric structures of the NiMo/TiO2 surface, which results in an easier cleavage of the N-H bond and desorption of reaction intermediates.

Automated summary

In this study, a supported amorphous catalyst NiMo/TiO2 was synthesized, which efficiently decomposes hydrous hydrazine to produce hydrogen with excellent catalytic properties. The strong synergistic interaction between the support TiO2 and NiMo nanoparticles, as well as the doping of Mo leading to changes in the surface structure of NiMo/TiO2, contributed to the easier cleavage of the N-H bond and desorption of reaction intermediates.