Activity and characterization of modified Cr2O3/ZrO2 nano-composite catalysts for oxidative dehydrogenation of ethane to ethylene with CO2

✍ Scribed by Shuang Deng; Huiquan Li; Songgeng Li; Yi Zhang

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 606 KB
• Volume: 268
• Category: Article
• ISSN: 1381-1169
• DOI: 10.1016/j.molcata.2006.12.033

✦ Synopsis

Cr 2 O 3 /ZrO 2 nano-composite catalysts modified with Ni, Fe, Co, Mn oxides respectively were synthesized by coupling co-precipitation with azeotropic distillation method. The effect of modifiers on the catalytic activity in the dehydrogenation of ethane with CO 2 was investigated. The modifiers exhibited different effects on catalytic behavior. Fe, Co and Mn oxides markedly increased ethylene selectivity, but the Ni 5 -Cr 10 /Zr nano-composite catalyst mainly favored side reactions-the reforming and cracking reactions. The Fe 5 -Cr 10 /Zr nano-composite catalyst exhibited an excellent performance in this reaction, producing 50.05% ethylene yield at 53.72% ethane conversion at 650 • C. The modified Cr 2 O 3 /ZrO 2 nanocomposite catalysts were characterized by BET, TEM, XRD, XPS, CO 2 -TPD and NH 3 -TPD techniques. The characterization indicated that weak acid sites are involved in ethane activation, and strong acid-base pairs promote the reforming and cracking reactions. The distribution of chromium species, oxygen species and base/acid property on the surface of catalyst cooperatively determined the catalytic activity in dehydrogenations of ethane to ethylene using CO 2 as an oxidant.