Ethane Oxidative Dehydrogenation over Pt-Rare Earth Intermetallic Compounds with CO₂ as Soft Oxidant

Abstract

Intermetallic Pt-M (M = La, Y, and Sc) nanoparticles supported on zeolite nanosponge (ZNS) were synthesized and investigated for ethane oxidative dehydrogenation (EOD) with CO 2 as a soft oxidant. Among all the catalysts examined, ZNSsupported Pt 5 La 1 nanoparticles had the best dispersion with an average particle size of 1.25 nm and the highest CO uptake of 34.7 μmol g −1 , surpassing the catalytic performance by 37% ethane conversion and 28% ethylene yield. The XPS results confirmed that some La species co-exist with Pt 5 La 1 in the form of LaO x . LaO x facilitated the facile engagement of CO 2 , leading to enhanced catalyst stability and improved CO 2 conversion. Furthermore, the LaO x -catalyzed reverse Boudouard reaction (CO 2 + C → 2CO) aided in the partial removal of deposited carbonaceous coke during the catalytic reaction. Apart from that, the gradual decrease after each regeneration cycle was inevitable due to the surface metal sintering.