(30f) Reaction Mechanisms and Kinetics Towards Highly Selective Catalytic Conversion of Bio-Based 5-HMF to Value-Added Chemicals with Bimetallic Nickel-Based Catalysts

Hydroxymethylfurfural (HMF) is an important platform chemical with tremendous potential that can be produced from renewable resources, specifically lignocellulosic biomass [1]. Since HMF contains three essential functional consistuents (a carbonyl group in the form of an aldehyde, an alcohol, and furan ring), a wide range of bio-based chemicals can be produced with HMF as an intermediate [2]. The catalytic conversion route with the most promise is hydrodeoxygenation (HDO) which occurs at moderate temperatures (180-250ËšC), high hydrogen pressures (30-50 bar), and in the presence of heterogeneous catalysts [3]. Nickel was chosen as an effective transitional metal catalyst alongside selected promoters to modify the acidity of the catalyst to finely tune propduct selectivity. We present, for the first time, a systematic experimental and in silico study of HMF hydrotreatment towards industrially relevant bio-based chemicals.

Methods

HDO catalytic tests were conducted in 75 mL batch reactors and liquid-phase samples were collected to determine concentration of products as a function of time. Catalyst characterization was performed by temperature-programmed reduction (TPR), SEM, NH₃ and CO temperature-programmed desorption (TPD) to identify catalyst morphology, surface properties, and active site concentrations.

Results

A reaction pathway has been proposed and a novel representative kinetic model has been established that takes into consideration, determined via NH₃/ CO chemisorption, distinct concentration of active sites, and their influence on catalyst activity and product selectivity.

References

[1] Kohli, K., Prajapati, R., Sharma, B., Bio-based chemicals from renewable biomass for integrated biorefineries. Energies. 2019, 12, 233 Chemical Reactor Analysis and Design, second ed., Wiley, New York, 1990.

[2] Menegazzo, F., Ghedini, E., Signoretto, M., 5-Hydroxymethylfurfural (HMF) Production from Real Biomasses. Molecules. 2018, 23, 2201

[3] Nishimura, S., Ebitani, K., Catalytic Conversions of Biomass-Derived Furaldehydes Toward Biofuels. Intech. 2016, 51