First-principles based catalyst and solvent design for the selective conversion of biomass to platform chemicals

点击翻译按钮获取中文摘要

Canada has huge lignocellulosic biomass resources that can be utilized as an alternate source of carbon, without putting any stress on the nutritional needs of the population. To convert the biomass to value-added fuels and chemicals, it needs to be transformed into desired platform intermediates that can be integrated into the existing industrial infrastructure. Liquid phase catalytic processing of biomass is the only non-biological, thermochemical pathway for its selective conversion. However, screening and selection of solvent systems is a challenge, since solvents are not only benign solvation media but they alter the conversion and selectivity. Additionally, the formation of humins, which are insoluble condensation and polymerization by-products in biomass reactions, needs to be minimized to reduce carbon loss and catalyst deactivation. Hence, the proposed project aims to develop fundamental understanding of the role of solvent in biomass reactions and of the chemistry of the formation of humins and their precursors. Specific objectives include investigating the role of solvents (I) in modifying the adsorption configuration and energies of biomass moieties on the catalyst, (II) in altering reaction kinetics due to different relative stabilization of reactants and transition states and due to solvent dynamics and non-equilibrium solvation. Additionally, catalytic reaction mechanisms of the formation of humins and their precursors will be identified and solvent systems and catalyst functionalities promoting humins formation will be revealed. Based on the fundamental understanding developed in the project, optimum combination of solvent, catalysts and operating conditions will be proposed. The proposed project will be the first synergistic investigation in liquid phase biomass conversion, combining solvent effects, reaction mechanisms and humins formation. A multiscale molecular modeling approach, based on the solid foundations of first principles, will be implemented in the project, in synergy with experiments. Preliminary screening will be done using implicit solvation model in density functional theory and selected calculations will be performed in explicit solvent molecules, treated quantum mechanically. Ab initio molecular dynamics along with biasing methods like metadynamics will be implemented to investigate solvent effects. The principal investigator has the relevant expertise and track record to ensure the success of the project. Three PhD students and five undergraduate students will be trained in the project.