Transition metal doped cryptomelane-type manganese oxide for low-temperature catalytic combustion of dimethyl ether
2013; Elsevier BV; Volume: 220; Linguagem: Inglês
10.1016/j.cej.2013.01.061
ISSN1873-3212
AutoresMing Sun, Lin Yu, Fei Ye, Guiqiang Diao, Qian Yu, Zhifeng Hao, Yuying Zheng, Lixiang Yuan,
Tópico(s)Catalysts for Methane Reforming
ResumoThe 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 13 nm diameter and the length ranging from 50 to 220 nm. 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).
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