Applied Catalysis A: General, Vol.385, No.1-2, 14-21, 2010
The effect of V in La2Ni1-xVxO4+1.5x+delta on selective oxidative dehydrogenation of propane: Stabilization of lattice oxygen
In this study, the non-stoichiometric redox compounds La2NiO4+delta and La2Ni0.9V0.1O4.15+delta have been tested as an oxidant in selective oxidation of propane in pulse experiments at temperatures between 450 and 650 degrees C. The oxygen contents in the samples at different temperatures were calculated based on backtitration with O-2 pulses as well as on TGA. In the case of La2Ni0.9V0.1O4.15+delta over-stoichiometric oxygen was the only active species, responsible for the formation of CO2, C3H6, C-2 H-4 and CH4 while pulsing propane at all investigated temperatures. Contrary, the reactive species in La2NiO4+delta changed from over-stoichiometric oxygen only at 450 degrees C. to both over-stoichiometric and lattice oxygen at 550 degrees C, to lattice oxygen only at 650 degrees C. The activation of lattice oxygen and the consequent formation of Ni metal were detrimental for selectivity to propylene as formation of COx, CH4 and coke mainly occurred and no olefins were formed. (c) Published by Elsevier B.V.