Selective hydrodeoxygenation of biomass pyrolysis oil and lignin-derived oxygenates to cyclic alcohols using the bimetallic NiFe core-shell supported on TiO2

Abstract

TiO2-supported Ni catalysts are promising candidates that can be used to achieve biomass valorization following the selective hydrodeoxygenation (HDO). Their catalytic activity can be tuned and they are characterized by strong metal–support interaction (SMSI). The SMSI observed at the interfaces of Ni nanoparticles (NPs) and the TiO2 support was tuned by adding Fe and subjecting the synthesis system to hydrothermal treatment conditions. The prepared catalysts promoted the selective conversion of alkyl methoxyphenols, including lignin-derived guaiacol, to saturated cyclic alcohols. The low Fe content (∼1.5 wt%) in Ni/TiO2 significantly promoted the formation of cyclohexanol from guaiacol (rate: 183 molcyclohexanol·molNi−1·h−1; selectivity: 85%). Alkyl methoxyphenols present in the biomass pyrolysis oil could be effectively converted into cyclic alcohols (yield: 71%). It was observed that the interfacial sites of highly dispersed NiFe-FeOx core–shell structures on the TiO2 support promote the demethoxylation of reactant to selectively produce cyclic alcohols.