Introducing K to Regulate the Electronic Structure of Perovskite-Type Oxide for the Efficient Reaction of Coke and Steam

The coking process hinders the long-term stable production of ethylene, so the rational design of the catalyst structure to achieve efficient in situ coke removal is the focus of research. Herein, a synthesis method for the controllable preparation of the perovskite molecular structure (A2B2O6, R-P, ABO3) was proposed, and the relationship between the perovskite structure and coke removal performance was revealed. DFT and experimental results jointly proved that the O 2p-band of the double perovskite shifts upward to the Fermi level, thus promoting the formation of free radical species. Double perovskite mainly promoted the contact reaction between the adsorbed hydroxyl radical and graphite carbon interface and also strengthened the gas–solid reaction between the free hydroxyl radical and graphite carbon, thus improving the conversion rate of coke. In the presence of double perovskite LaKSr0.17Fe1.5O6, the maximum coke conversion rate is 100%. This method provides a theoretical basis for the synthesis of heterogeneous catalysts.