Active sites for tandem reactions of CO ₂ reduction and ethane dehydrogenation

Abstract

Ethylene (C₂H₄) is one of the most important raw materials for chemical industry. The tandem reactions of CO₂-assisted dehydrogenation of ethane (C₂H₆) to ethylene creates an opportunity to effectively use the underutilized ethane from shale gas while mitigating anthropogenic CO₂ emissions. Here we identify the most likely active sites over CeO₂-supported NiFe catalysts by using combined in situ characterization with density-functional theory (DFT) calculations. The experimental and theoretical results reveal that the Ni-FeO _<i>x</i> interfacial sites can selectively break the C-H bonds and preserve the C-C bond of C₂H₆ to produce ethylene, while the Ni-CeO _<i>x</i> interfacial sites efficiently cleave all of the C-H and C-C bonds to produce synthesis gas. Controlled synthesis of the two distinct active sites enables rational enhancement of the ethylene selectivity for the CO₂-assisted dehydrogenation of ethane.