Propane CO2-oxidative dehydrogenation catalyzed by Pt-Sn supported on magnesium-chemically grafted SBA-15

Here reports the enhancement of PtSn catalysts supported on SBA-15 for propane CO2-oxidative dehydrogenation by incorporating magnesium oxide (MgO), with loadings ranging from 2 to 6 wt.%, using an alternative chemical grafting method involving a magnesium methoxide solution. The integration of MgO via chemical grafting, maintain the structural integrity of SBA-15 significantly boosting the Pt-Sn catalysts activity and stability. The optimal loading of 3.8 wt.% MgO (CMg4) yielded the highest propylene selectivity (92 %) and demonstrated lower selectivity toward cracking products. The incorporation of magnesium shifted the surface acidity, increasing Lewis acid sites and decreasing Brønsted acid sites. This change led to a reduction in the formation of undesirable byproducts such as CO, CH4, C2H4, and C2H6, thereby enhancing the selectivity towards propylene.