HCl存在下CeO_2基催化剂上乙烷氧化脱氢制乙烯

Oxidative dehydrogenation of ethane to ethylene in the presence of HCl over CeO_2-based catalysts

报道了一种HCl存在时温和条件下的乙烷氧化脱氢制乙烯催化转化新途径.研究发现,在多种金属氧化物催化剂中,CeO2呈现最佳乙烯生成的催化性能.与纳米粒子相比,具有棒状和立方体状形貌的CeO2纳米晶具有较高的乙烷转化率和乙烯选择性.以MnOx修饰CeO2可进一步提高催化性能.在8 wt%MnOx-CeO2催化剂上,723 K反应2 h时乙烷转化率和乙烯选择性分别为94%和69%.该催化剂性能稳定,反应100 h乙烯收率可保持在65%–70%.HCl的存在对乙烯的选择性生成起着至关重要的作用,一部分乙烯来自于氯乙烷的脱HCl反应.

This article reports a new catalytic route for the oxidative dehydrogenation of ethane to ethylene in the presence of HCl at moderate temperatures. CeO2 was found to be the most efficient catalyst for the production of ethylene from the variety of metal oxides examined in this work. CeO2 nanocrys‐tals with rod and cube morphologies showed higher ethane conversions and ethylene selectivities than CeO2 nanoparticles. The modification of CeO2 by MnOx further enhanced the catalytic perfor‐mance. Ethane conversion of 94% and ethylene selectivity of 69% were obtained after 2 h of reac‐tion at 723 K over an 8 wt% MnOx-CeO2 catalyst. This catalyst was stable and the ethylene yield could be sustained at 65%–70% over 100 h of reaction. The presence of HCl played a key role in the selective production of C2H4, and some of the C2H4 was probably formed from chloroethane by de‐hydrochlorination.