Characteristics and catalytic behavior of different platinum supported catalysts in the selective hydrogenation of soybean oil

Abstract

Platinum (Pt) catalysts supported on TiO2, ZrO2, activated carbon, and multi-walled carbon nanotubes were prepared by the wet impregnation method. The characterization of the obtained catalysts was performed with XRD, ICP-AES, TEM and N2-adsorption. Their catalytic behavior during the selective hydrogenation of soybean oil was also studied. The results showed that compared with the commercial Raney Ni, all the platinum-catalysts exhibited better activity and lower selectivity towards trans isomer during the partial hydrogenation of soybean oil. Especially the Pt/ZrO2 catalyst had the lowest selectivity towards the formation of trans C18:1 isomers and stearic acid. The results also showed that the metal loading had little impact on the hydrogenation activity and selectivity. Meanwhile, the acid value of hydrogenated oil over platinum-catalysts was less than 1.0 (KOH)/(mg/g). The hydrogenated oil over platinum-catalyst indicated good melting characteristics and solid fat content. These results demonstrated that Pt/ZrO2 catalyst could be a good alternative of Raney Ni to reduce the formation of trans fatty acid and saturated fatty acid in hydrogenated soybean oil, and meanwhile ensure the physicochemical quality requirements of hydrogenated oils.