On the reduction of CO2 footprint via selective hydrodeoxygenation by ZnO–Ti3C2Tx catalyst under solvent-free conditions

Abstract

Biomass-derived fatty acids are essential feedstock for producing liquid fuels and value-added chemicals with significantly low CO₂ footprints. Herein, Ti₃C₂T_x and ZnO–Ti₃C₂T_x catalysts were synthesized and demonstrated for the selective hydrodeoxygenation reaction (HDO) of methyl oleate (MO) as a model compound. The synthesized ZnO–Ti₃C₂T_x catalyst showed 100% conversion of MO with >90% selectivity for the HDO product (n-C18). In addition, the pure Ti₃C₂T_x demonstrated 100% conversion with a selectivity of 67% for n-C17 hydrocarbon via the decarboxylation route. The highest reduction of CO₂ footprint is achieved at 280 °C and 30 bar H₂ pressure under solvent-free conditions using ZnO–Ti₃C₂T_x. The catalyst is recyclable and reusable for five test cycles. The high catalytic selectivity of the ZnO–Ti₃C₂T_x catalyst towards HDO is attributed to the synergic effect of the Ti and ZnO active sites and the thermally stable structure. This study offers an efficient route for converting edible and non-edible vegetable oils to biofuels by controlling CO₂ production.