Integrated CO2 capture and conversion (iCCC) technology combines CO2 adsorption and catalytic conversion within a single reactor, thereby avoiding energy-intensive adsorbent regeneration and CO2 transportation processes, and offering a promising alternative to conventional stepwise capture and conversion routes. Coupling ethane oxidative dehydrogenation (ODHE) with the iCCC process, utilizing captured CO2 as a mild oxidant, can not only overcome the thermodynamic equilibrium limitations of dehydrogenation reactions to enhance ethylene yield, but also achieve the resource utilization of CO2, forming a promising iCCC–ODHE pathway. Nevertheless, this process faces competition from the dry reforming of ethane (DRE) side reaction, which essentially stems from the selective cleavage of C–H versus C–C bonds in ethane molecules. Moreover, the synergistic mechanism between adsorption and catalysis remains unclear. Therefore, developing highly selective adsorbent-catalyst dual functional system and rationally designing the coupling mode between adsorption and catalytic sites are crucial for achieving efficient iCCC–ODHE.
Recently, a research team led by Prof. Jun Hu from East China University of Science and Technology, China revealed the contributions of local catalytic environments to the iCCC-ODHE performance through tailoring the catalyst itself and the proximity-governed effect. The results were published in Chinese Journal of Catalysis (DOI: 10.1016/S1872-2067(26)65101-7 ).
Integrated CO2 capture and ODHE was achieved by coupling Co-ZSM-5 catalysts with Ca4MgO5 adsorbents.Through maximizing the relative concentration of Co2+ in the catalysts of Co-ZSM-5-1.5, highly dispersed Co2+ sites in the confined channels significantly enhanced ethylene yield. More importantly, the granule-stacking configuration of the fixed bed optimized the adsorbent-catalyst proximity, achieving a critical local CO2 microenvironment for efficient iCCC-ODHE.The optimized adsorbent-catalyst system achieved a CO2 capture capacity of 10.8 mmol g-1 witha 54.3% ethane conversion and 45.4% ethylene yieldat 650 °C.
Combined with in-situ DRIFTS, DFT calculationsrevealed that the relatively lower local CO2 concentration showed a significant steric and electronic advantage for lowing the cleavage energy of the first C–H bond, and facilitating the pathway of ethylene production through the sequential consumption of the produced *H by the released CO2 from the captured state. Therefore, this insight into the local catalytic environment provides a promising iCCC-ODHE strategy toward carbon neutrality.
About the Journal
Chinese Journal of Catalysis is co-sponsored by Dalian Institute of Chemical Physics, Chinese Academy of Sciences and Chinese Chemical Society, and it is currently published by Elsevier group. This monthly journal publishes in English timely contributions of original and rigorously reviewed manuscripts covering all areas of catalysis. The journal publishes Reviews, Accounts, Communications, Articles, Highlights, Perspectives, and Viewpoints of highly scientific values that help understanding and defining of new concepts in both fundamental issues and practical applications of catalysis. Chinese Journal of Catalysis ranks among the top one journals in Applied Chemistry with a current SCI impact factor of 17.2. The Editors-in-Chief are Profs. Can Li and Tao Zhang.
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