Direct dehydrogenation of isobutane to isobutene over carbon catalysts

Various carbon materials were found to function as highly active catalysts for the direct dehydrogenation of isobutane without the addition of oxidizing gases (such as oxygen, carbon dioxide or nitrous oxide) or the deposition of metal particles. Among these materials, coconut shell activated carbon (CSAC) generated the highest isobutane conversion of 70%. It is notable that the CSAC catalyst exhibited a high degree of catalytic stability that was comparable to that of conventional catalysts and was able to maintain a selectivity for isobutene of approximately 76%. The most important factor with regard to the catalytic activity of both fresh and used carbon catalysts was determined to be the specific surface area of the material. These results are unique since they indicate that various carbon materials, including deposited coke, can behave as effective catalysts for the isobutane conversion reaction even without the presence of functional groups. (C) 2015, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.