Unveiling the Role of Active Oxygen Species in Oxidative Dehydrogenation of Ethane with CO<sub>2</sub> over NiFe/CeO<sub>2</sub>
Man Guo, Kai Feng, Yaning Wang, Binhang Yan
Abstract
Abstract The oxidative dehydrogenation of ethane (ODH) assisted by CO 2 to produce ethylene is inevitably accompanied by the side reaction of dry reforming (DRE) to produce carbon monoxide. However, the key factor determining the dehydrogenation selectivity is still ambiguous. In this paper, four different NiFe/CeO 2 catalysts were synthesized via an impregnation method over four types of CeO 2 . The dehydrogenation selectivity of the four catalysts ranged from 40 % to 83 %. Temperature‐programmed surface reaction and transient response experiments reveal the existence of two types of oxygen species over NiFe/CeO 2 catalysts. FeO x layers exist as an oxygen species supply buffer over CeO 2 supports. Weakly electrophilic oxygen species supplied by FeO x overlayers could participate in producing C 2 H 4 while strong electrophilic oxygen species supplied by CeO 2 supports could participate in producing CO. The content of weakly electrophilic oxygen species is identified to be a rational descriptor of C 2 H 4 selectivity.