Enhancing Nickel-Based Catalysts for Hydrodeoxygenation: The Role of Sulfated and Phosphated Silica Supports

Abstract

The development of efficient catalysts for hydrodeoxygenation (HDO) is crucial for producing sustainable hydrocarbons from biomass-derived feedstocks. In this investigation, silica (SiO₂) supports were modified through sulfation and phosphatization treatments to enhance the performance of nickel-based catalysts for HDO reactions. The modified silica supports, SiO₂-S (sulfated) and SiO₂-P (phosphated), were characterized using XRD, FTIR, N₂ physisorption, and FE-SEM techniques to assess their structural changes, surface area, and nickel dispersion. SiO₂-S exhibited the highest surface acidity and pore volume, resulting in superior nickel dispersion and smaller particle sizes. The catalytic performance was evaluated in HDO reactions, with Ni/SiO₂-S achieving the highest hydrocarbon selectivity (89.3%), particularly for C17 hydrocarbons, attributed to the enhanced Brønsted acid sites. Ni/SiO₂-P also improved hydrocarbon production compared to untreated SiO₂, albeit with lower selectivity. This research elucidates the critical role of surface acidity and support modification in optimizing nickel-based catalysts for HDO reactions.