Correlation between CO Oxidation and Coke Oxidation over Cerium-Zirconium Mixed Oxides

摘要

Coke formation reactions at high temperature are common in chemical processes, such as on catalysts in hydrocarbon cracking [1] and on reactor walls in steam cracking [2]. While carbon rejection via coke may be desirable in some processes (e.g. FCC), it often leads to catalyst deactivation, poor heat transfer through reactor walls and even damage to the reactor. Thus, mitigation of coke by catalytic oxidation reactions can be an important remediation step in high temperature processes. Cerium-zirconium mixed oxides have demonstrated higher oxidation activity than cerium oxide at high temperatures because of their increased thermal stability [3]. However, kinetic studies of coke oxidation catalyzed by cerium-zirconium mixed oxides are still lacking. Hence, we investigated the reaction kinetics of coke oxidation catalyzed by cerium-zirconium mixed oxides and explored the relationship between mixed oxide composition and activity for oxidation of both coke and CO.