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The oxidative dehydrogenation (ODH) of isobutane over Cr2O3/La2(CO3)3 has been investigated in a low-pressure Knudsen cell reactor, under conditions where the kinetics of the primary reaction steps can be accurately determined. By heating the catalyst at a constant rate from 150-300℃, temperature fluctuations due to non-equilibrium adsorption are minimized. The evolved gas profiles show that ODH to isobutene and water is a primary reaction pathway, while carbon dioxide, which forms from the catalyst during reaction, is the only other product. This CO2 evolution may enhance the activity of the catalyst. Isobutene formation proceeds with the participation of lattice oxygen from the Cr2O3/La2(CO3)3 catalyst. The intrinsic Arrhenius rate constant for the ODH of isobutane isk(s-1) = 1011.5±2.2exp{-((55±5) -ΔHads kJmol-1)/RT}The small pre-exponential factor is expected for a concerted mechanism and for such a catalyst with a small surface area and limited porosity.
The oxidative dehydrogenation (ODH) of isobutane over Cr2O3 / La2 (CO3) 3 has been investigated in a low-pressure Knudsen cell reactor, under conditions where the kinetics of the primary reaction steps can be determined. By heating the catalyst at a constant The evolved gas profiles show that ODH to isobutene and water is a primary reaction pathway, while carbon dioxide, which forms from the catalyst during reaction, is the only The intrinsic evolution of Arrhenius rate for the ODH of isobutane isk (s-1) isotherm formation is obtained with the participation of lattice oxygen from the Cr2O3 / La2 (CO3) 3 catalyst. = 1011.5 ± 2.2exp {- ((55 ± 5) -ΔHads kJ mol-1) / RT} The small pre-exponential factor is expected for a concerted mechanism and for such a catalyst with a small surface area and limited porosity.