Propane oxydehydrogenation over molybdate-based catalysts

Journal Article · Tue Apr 15 04:00:00 EDT 1997 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1997.1568· OSTI ID:563491

Stern, D L; Grasselli, R K ^[1]

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1. Mobil Technology Company, Paulsboro, NJ (United States)

Single and binary metal molybdates, supported on silica (80 wt% active phase/20 wt% SiO{sub 2}), having the formula AMoO{sub 4}, where A = Ni, Co, Mg, Mn, and/or Zn, and some ternary molybdates having the formula Ni{sub 0.45}Co{sub 0.45}X{sub 0.066}MoO{sub 4}, where X = P, Bi, Fe, Cr, V, and Ce, were investigated for the oxydehydrogenation of propane to propylene. The reaction is catalytic and is first order in propane disappearance, consistent with the abstraction of a methylene hydrogen being the rate limiting step. Propane conversion and yields of propylene produced vary greatly with the choice of the A metal of the molybdate and the surface area of the catalyst. At 560{degrees}C and atmospheric pressure, the highest propane conversion and highest propylene yields are obtained with NiMoO{sub 4}/SiO{sub 2} (16% at 27% conversion), closely followed by Ni{sub 0.5}Co{sub 0.5}MoO{sub 4}/SiO{sub 2}. The molybdenum content of the compositions greatly influences the catalytic activity and useful product yields. The effect is largest for the Ni-molybdate system whose optimum lies at stoichiometry. The optimum activity of Co-molybdate lies at molybdenum lean compositions. Binary Ni-Co-molybdates are less sensitive to molybdenum level, offering a conveniently stable catalytic system for further mechanistic and technological optimization studies. These studies suggest, that the Ni-Co molybdate system provides an alternate to V-based catalysts for the activation of light paraffins. Futuristically, it holds promise as the paraffin activating component of a two component catalyst system for the direct conversion, in a single reactor, of propane to acrylic acid or acrylonitrile, with the second component being composed of one of the well known olefin converting, multicomponent mixed metal molybdates. 23 refs., 10 figs., 2 tabs.

• OSTI ID: 563491
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 2 Vol. 167; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
40 CHEMISTRY
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
COBALT COMPOUNDS
DEHYDROGENATION
HETEROGENEOUS CATALYSIS
MAGNESIUM COMPOUNDS
MANGANESE COMPOUNDS
MOLYBDATES
NICKEL COMPOUNDS
OXIDATION
PROPANE
ZINC COMPOUNDS