(114d) Engineering Bifunctional Catalytic Materials for Selective Synthesis of Biobased Chemicals

Scientists and engineers play a pivotal role in advancing clean energy technologies and a sustainable chemical industry, crucial for mitigating climate change and the limited availability of fossil resources. Furthermore, transitioning from fossil-based to renewable carbon sources is essential for decarbonizing the energy sector and aligning the chemical industry with sustainability goals. Lignocellulosic biomass is an abundant renewable carbon source with the potential to significantly advance a sustainable chemical industry producing transportation fuels and commodity chemicals. The main components of lignocellulosic biomass, polymerized carbohydrates, and monolignols, can be converted into various platform chemicals, including furans, carboxylic acids, alcohols, aromatics, and alkanes, through reactions that form or break C-O, C-H, and C-C bonds. However, selective transformations to these platform chemicals remain a challenge over heterogeneous catalysts.

We have developed a series of bifunctional heterogeneous catalytic materials comprised of supported hydrogen dissociating metal centers (Pd, Rh, Pt) coupled with redox metal oxide species (MoO_x, ReO_x, WO_x) that maximize activity, selectivity, and stability for the hydrodeoxygenation (HDO) of biomass-derived polyols and dicarboxylic acids for platform chemical production. Through an integrated approach based on materials synthesis, advanced characterization, and kinetic measurements, we unravel the mechanisms governing selective C-O bond activation over these bifunctional catalysts. We interrogate the specific role of the noble metal, metal oxide species, and catalyst support in the selective HDO of different biobased substrates, such as 1,4-anhydroerythritol, tartaric acid, and glycerol. Furthermore, we provide valuable insights for developing catalysts with tailored active sites for HDO chemistries by establishing structure-function-performance relationships.