Hydrothermal deoxygenation of triglycerides over carbon-supported bimetallic PtRe catalysts without an external hydrogen source

Abstract

Hydrothermal deoxygenation is a promising route for producing oxygen-free hydrocarbons from triglycerides even without an external H-2 source. In this study, PtRe catalysts supported on various carbons were investigated for this reaction. The PtRe catalysts showed enhanced rates of glycerol reforming for in situ H-2 production and higher deoxygenation activities, as compared to Pt catalysts. Consequently, the PtRe catalysts showed superior hydrothermal deoxygenation performances. Carbon supports with low oxygen content (e.g., CNT) were beneficial for supporting highly dispersed and well alloyed PtRe particles, which were prerequisites for high catalytic activity. Oxygen-rich carbon surfaces caused the segregation of Re, causing low catalytic activity. PtRe/CNT showed the best performance, yielding 72 wt% n-paraffin (theoretical yield: 79 wt%) from palm oil. The catalyst could be recycled for 5 times without significant loss of activity.