Cyclohexane oxidation and carbon deposition over metal oxide catalysts

Catalytic activity of V, Mn, Ni, Cu, Zn, Mo, Zr and Cc oxides over an a-alu mina support was evaluated for cyclohexane oxidation under oxygen deficient conditions in order to understand the relation between carbon deposition a nd catalytic activity/selectivity. Carbon formation over the catalysts duri ng the oxidation reaction was measured by means of Fourier transformed infr ared spectroscopy (FTIR). Catalysts Mn/Al2O3 and Ce/Al2O3, which are select ive for deep oxidation of cyclohexane, possessed relatively carbon free sur faces. The catalysts with relatively high carbon deposition (V, Ni, Cu, Zn, Mo and Zr) produced CO in addition to CO2. Traces of formaldehyde were pro duced over the catalysts Mo and V. (C) 2001 Elsevier Science Ltd. All right s reserved.