Oxidative dehydrogenation of ethane with CO2 over Cr supported on submicron ZSM-5 zeolite

A series of submicron ZSM-5-supported chromium oxide catalysts were prepared and characterized by XRD, N-2 adsorption, Al-27 MAS NMR, SEM, XPS, laser Raman spectroscopy and diffuse reflectance UV-Vis spectroscopy. The catalytic performance of these materials during ethane dehydrogenation in the presence of CO2 was investigated. The catalysts exhibited both high activity and stability, with an ethane conversion of similar to 65% and ethylene yield of similar to 49% without any obvious deactivation following 50 h. Characterization results show that the excellent catalytic performance results from the high degree of dispersion of CrOx species on the submicron ZSM-5 surface. Both a high Si/Al ratio and the use of the Na-form of the ZSM-5 support were found to favor CrOx dispersion. The promotional effect of CO2 on the dehydrogenation reaction was quite evident and can be attributed to the reverse water-gas shift reaction. (C) 2015, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.