Potassium-assisted activation strategy regulating metal-support interaction to promote hydrothermal hydrogenation/deoxygenation of palmitic acid

Abstract

The catalytic preparation of renewable fuels from biomass using palmitic acid as a model compound of bio-oil has been a research focus in the field of renewable energy in recent years. However, the development of highly active, low-priced, and hydrothermal stable catalysts remains a challenging task. Here, a trace potassium-assisted activation method is proposed to improve the hydrothermal hydrogenation/deoxygenation activity of palmitic acid in this work. The conversion was successfully increased from 71.7% to 96.2%, and the total yield of alkanes was increased from 38.0% to 82.5% at 260 °C for 180 min. The research results indicate that additional defect sites and a small amount of P doping in coconut shell carbon are generated with K3PO4-assisted activation, enhancing the stronger metal-support interaction, and improving the hydrothermal stability and catalytic activity of the catalyst. XPS and H2-TPR jointly illustrate that K3PO4-assisted activation makes nickel species on the surface of the catalyst more easily reduced, resulting in a significant increase in the Ni0/Ni2+ ratio and oxygen vacancies during the carbothermal reduction process. This work provides a new strategy to further improve catalytic activity of bio-oil deoxygenation.