Mechanistic study of 1,1-dimethylhydrazine transformation over Pt/SiO2 catalyst

Andrei V Smirnov; Pavel A Kots; Maksim A Panteleyev; Irina I Ivanova

doi:10.1039/c8ra07769j

Mechanistic study of 1,1-dimethylhydrazine transformation over Pt/SiO₂ catalyst

RSC Adv. 2018 Nov 1;8(64):36970-36979. doi: 10.1039/c8ra07769j. eCollection 2018 Oct 26.

Authors

Andrei V Smirnov^{1

2}, Pavel A Kots¹, Maksim A Panteleyev¹, Irina I Ivanova^{1

2}

Affiliations

¹ Department of Chemistry, Lomonosov Moscow State University Leninskiye Gory 1, bld. 3 11991 Moscow Russia.
² A.V. Topchiev Institute of Petrochemical Synthesis Leninskiye prospect 29 11991 Moscow Russia.

Abstract

Catalytic oxidation of 1,1-dimethylhydrazine (UDMH) with molecular oxygen over Pt/SiO₂ was studied by in situ FTIR spectroscopy coupled with online MS monitoring of the gas phase. An unusual two-step oxidation process was detected in experiments with the pulse UDMH feeding: initial UDMH oxidation over a fresh platinum surface quickly terminates due to the blockage of active sites; a time-separated second oxidation step corresponds to combustion of the surface residue. This residue consists of C[triple bond, length as m-dash]N nitrile groups formed via decomposition of the products of non-oxidative UDMH conversion, such as dimethylamine. The two-step oxidation picture is observed over a broad range of reaction temperatures and oxygen to UDMH ratios.