Density Functional Theory Study on the Hydrogen Extraction Reaction Mechanism of Unsymmetrical Dimethylhydrazine with N02 Affected by Fullerenes C70

To explore the feasibility of using fullerenes (C70) as a catalyst for the decomposition of unsymmetrical dimethylhydrazine (UDMH) propellants, the interactions between UDMH molecules and C70 cluster molecules were conducted using the density functional theory (DFT). The adsorption behavior and decomposition path of UDMH on C70 surface were analyzed. The activation energy and reaction heats of the hydrogen extraction reaction of UDMH in the presence of C70 were calculated and obtained. The results show that UDMH molecules exhibit two adsorptin configurations on the surface of C70, mainly undergoing physical adsorption with relatively low adsorption energy. The addition of C70 molecules does not change the initial and secondary reaction site of UDMH decomposition, but exhibites sequential occurrence on the NH2 groups during the hydrogen extraction reaction with NO2. Compared with the decomposition of pure UDMH, the activation energy of the initial elementary reaction of UDMH decomposition in two adsorption configurations decrease by 19.4 kJ/mol and 21.1 kj/mol, respectively, and the heat of reaction reduces by 24.2 kj/mol and 27 kj/mol, respectively. Therefore, C70 has catalytic ability for the first two steps of UDMH decomposition, promoting the decomposition of UDMH. © 2024 China Ordnance Industry Corporation. All rights reserved.