Structure-Activity Relationships of Pt-WOx/Al2O3 Prepared with Different W Contents and Pretreatment Conditions for Glycerol Conversion to 1,3-Propanediol

Turning waste glycerol into a fundamental chemical used in the petrochemical industry offers an opportunity to reduce not only waste from biodiesel production but also the consumption of petroleum-based chemicals. In the present work, glycerol was converted to 1,3-propanediol over Pt-WOx/Al2O3 catalysts, while focusing on the influence of W loading contents (10-20 wt.%) and catalyst pretreatment conditions, specifically the calcination temperatures of WOx/Al2O3 (700-900?), calcination temperatures of Pt-WOx/Al2O3 (350-450 ?) and reduction temperatures of Pt-WOx/Al2O3 (300-400 ?). The characteristics of the catalysts were identified by applying N-2-sorption, XRD, Raman, CO pulse chemisorption, NH3-TPD, H-2-TPR, H-2-TPD, SEM and TEM-EDS and XPS. The W loading contents and pretreatment conditions strongly affected the activity and products selectivity. The W content and calcination temperature of WOx/Al2O3 at 15 wt.% and 800 ?, respectively, were evaluated as the most suitable in providing optimum W-O-W clusters to generate H delta+ which was a key parameter for the generation of 1,3-propanediol. The calcination and reduction temperatures of Pt-WOx/Al2O3 at 400 ? and 350 ?, respectively, were mandatory to sufficiently convert PtCl2 to Pt3O4 and Pt3O4 to metallic Pt, respectively. The optimized Pt-WOx/Al2O3 catalyst achieved a high glycerol conversion (44.7%) with high selectivity toward 1,3-propanediol (45.1%) under a reaction temperature and pressure of 220 ? and 60 bar, respectively.

Automated summary

Converting waste glycerol into 1,3-propanediol through catalysis offers a way to reduce waste from biodiesel production and the use of petroleum-based chemicals. This study investigated the effects of W loading contents and catalyst pretreatment conditions on glycerol conversion using Pt-WOx/Al2O3 catalysts. The optimized catalyst achieved high glycerol conversion (44.7%) and selectivity towards 1,3-propanediol (45.1%) under specific reaction conditions.