Oxidative dehydrogenation of isobutane over LaBaSm oxide catalyst - Influence of the addition of CO2 in the feed

Oxidative dehydrogenation (ODH) of isobutane over LaBaSm oxide catalyst in the temperature range 450-600 degrees C, and the influence of the addition of CO2 into the feed were investigated. It was found that LaBaSm oxide is a n active and stable catalyst for ODH of isobutane. Upon reaction conditions the specific surface area decreases and a new phase, La2O(CO3)(2), is form ed, which causes an increase in the surface specific conversion. The select ivity to isobutene as well as isobutane conversion can be improved by addin g CO2 into the feed. These effects may be explained as due to the combined effects of improvement of the active phase formation and the competition be tween molecular O-2 and CO2 adsorption on the sites which are responsible f or total oxidation. (C) 2000 Elsevier Science B.V. All rights reserved.