Synthesis, Characterization and Catalytic Evaluation of Chromium Oxide Deposited on Titania-Silica Mesoporous Nanocomposite for the Ethane Dehydrogenation with CO2

Ti modification of mesoporous silica support has been reported as an effective way to enhance Cr-Ti-Si interactions that, in turn, impact the catalytic dehydrogenation of ethane with CO2. However, such modification necessitates a repeated, time-consuming and tedious process. In this work, a simple, fast and facile approach has been utilized to synthesize chromium-oxide-loaded titania-silica mesoporous nanocomposites. A series of Cr(y)/Ti(x)-Si mesoporous nanocomposite catalysts with varying Ti and Cr contents were prepared and tested in the dehydrogenation of ethane with carbon dioxide. The as-synthesized catalysts were characterized by XRD, TEM, SEM, BET, UV-Vis-DR, XPS and H-2-TPR techniques. The effect of titanium content, as well as chromium loading on the performance of the prepared Cr(y)/Ti(x)-Si catalysts, was investigated. It was found that 2.2 and 8 wt % are the optimum titanium and chromium contents in the synthesized catalysts for obtaining the highest catalytic activity. The superior catalytic performance of the Cr(8)/Ti(2.2)-Si catalyst can be attributed to a higher dispersion of the Cr species, as well as a higher content of the redox Cr species on the surface of the Cr/Ti-Si catalyst. The results showed that the Cr(8)/Ti(2.2)-Si catalyst efficiently dehydrogenated C2H6 in the presence of CO2 giving a 52.3% ethane conversion and 48.0% ethylene yield at 700 degrees C reaction temperature.