Transition metal doped cryptomelane-type manganese oxide for low-temperature catalytic combustion of dimethyl ether

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 220; pp. 320 - 327
• Main Authors: Sun, Ming, Yu, Lin, Ye, Fei, Diao, Guiqiang, Yu, Qian, Hao, Zhifeng, Zheng, Yuying, Yuan, Lixiang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 15.03.2013; Elsevier
• Subjects: Applied sciences; Catalysis; Catalysts; catalytic activity; Catalytic combustion; Catalytic reactions; Chemical engineering; Chemistry; Chromium; Combustion; Copper; Cryptomelane-type manganese oxide; Dimethyl ether; Emission analysis; Exact sciences and technology; General and physical chemistry; Inductively coupled plasma; manganese oxides; nanorods; Nanostructure; Reactors; surface area; temperature; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; transition elements; Transition metal; Transition metal; Dimethyl ether; Catalytic combustion; Cryptomelane-type manganese oxide; Transmission electron microscopy; Morphology; Carbon dioxide; Oxidation; Surface area; Catalyst activity; Catalyst; Low temperature
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2013.01.061

► Fe, Co, Ni, Cu, Cr doped OMS-2 catalyst were prepared and applied to the DME catalytic combustion. ► Cu-OMS-2 has the best activity with a T10 of 171°C and a T90 of 180°C. ► The activity of M-OMS-2 catalyst were greatly influenced by the type of doped metals. ► The activity is related with surface area, average oxidation state and redox properties. The catalysts of transition metals (Fe, Co, Ni, Cu, Cr) doped cryptomelane-type manganese oxide (M-OMS-2) were prepared and investigated for the catalytic combustion of dimethyl ether (DME). The catalysts were characterized by XRD, FT-IR, BET, TEM, ICP-AES, XPS and H2-TPR techniques. The effects of surface area, the average oxidation state, and the redox properties on catalytic activities were studied. The results showed that 100% CO2 selectivity can be realized over the doped OMS-2 catalysts. The M-OMS-2 catalysts displayed the nanorod morphology with a 13nm diameter and the length ranging from 50 to 220nm. The Cu doped OMS-2 catalyst exhibited the best activity, achieving the light-off temperature (the temperature acquired for 10% DME conversion, T10) and full-conversion temperature (the temperature acquired for 90% DME conversion, T90) of 171 and 180°C, respectively. DME catalytic combustion over M- OMS-2 catalysts was found to follow a Mars–van-Krevelen mechanism with the presence of redox between Mn4+/Mn3+ and Mm+/M(m−1)+ (M=Fe, Co, Ni, Cu, Cr).