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

Intermetallic Pt-M (M = La, Y, and Sc) nanoparticles supported on zeolite nanosponge (ZNS) were synthesized and investigated for ethane oxidative dehydrogenation (EOD) with CO2 as a soft oxidant. Among all the catalysts examined, ZNS-supported Pt5La1 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 Pt5La1 in the form of LaOx. LaOx facilitated the facile engagement of CO2, leading to enhanced catalyst stability and improved CO2 conversion. Furthermore, the LaOx-catalyzed reverse Boudouard reaction (CO2 + 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.