Haneda Masaaki, Katsuragawa Yuya, Nakamura Yuichiro, Towata Atsuya
Advanced Ceramics Research Center, Nagoya Institute of Technology, Tajimi, Japan.
Frontier Research Institute for Materials Science, Nagoya Institute of Technology, Nagoya, Japan.
Front Chem. 2018 Nov 22;6:581. doi: 10.3389/fchem.2018.00581. eCollection 2018.
The promoting effect of CeO on the catalytic performance of YO, which is moderately active catalyst, for the oxidative coupling of methane (OCM) reaction was investigated. The addition of CeO into YO by coprecipitation method caused a significant increase in not only CH conversion but also C (CH/CH) selectivity in the OCM reaction. C yield at 750 °C was increased from 5.6% on YO to 10.2% on 3 mol% CeO/YO. Further increase in the CeO loading caused an increase in non-selective oxidation of CH to CO. A good correlation between the catalytic activity for the OCM reaction and the amount of H consumption for the reduction of surface/subsurface oxygen species in the H-TPR profile was observed, suggesting the possibility that highly dispersed CeO particles act as catalytically active sites in the OCM reaction. The O/O isotopic exchange reaction suggested that the beneficial role of CeO in the OCM reaction is to promote the formation of active oxygen species the simple hetero-exchange mechanism, resulting in the promotion of CH activation.
研究了CeO对中等活性催化剂YO在甲烷氧化偶联（OCM）反应中催化性能的促进作用。通过共沉淀法将CeO添加到YO中，不仅使OCM反应中的CH转化率显著提高，而且C（C2H4/C2H6）选择性也显著提高。750℃下的C2H4产率从YO上的5.6%提高到3mol%CeO/YO上的10.2%。CeO负载量的进一步增加导致CH非选择性氧化为CO。观察到OCM反应的催化活性与H-TPR谱中用于还原表面/次表面氧物种的H消耗量之间存在良好的相关性，这表明高度分散的CeO颗粒在OCM反应中可能充当催化活性位点。O/O同位素交换反应表明，CeO在OCM反应中的有益作用是通过简单的异质交换机制促进活性氧物种的形成，从而促进CH活化。
