The Direct Hydrodeoxygenation of Vegetable Oil over Pt- Sn/Al₂O₃ Catalysts

Abstract

The evolution of the structure of Pt–Sn/Al2O3 catalysts and their catalytic properties in the reaction of the reductive deoxygenation of rapeseed oil fatty acid triglycerides (FATGs) have been studied. It has been shown that the use of the heterometallic complex as a precursor with a tin to platinum molar ratio of 5 results in the formation of clusters of nanosized tin (2+; 4+) oxides and particles of a metastable PtSn3±d alloy on the surface of the catalyst after reductive activation. In the presence of this catalyst, the exhaustive conversion of the feed FATGs and the selectivity for hydrocarbons above 98% have been achieved. The gaseous products CO, CO2, and CH4 are formed in trace quantities. The results show that the deoxygenation occurs not via the known decarboxylation and decarbonylation route, but also through the step of the selective reduction of oxygen and almost complete suppression of cracking of the organic moieties of FATGs.