Benginur Demir

TL;DR: In this article, the authors investigated the effects of organic solvent mixtures with water on the kinetics of acid-catalysed dehydration reactions of relevance to biomass conversion, and demonstrated that the understanding of these solvation effects can be employed to optimize the rate and selectivity for production of the biomass platform molecule hydroxymethylfurfural from fructose.

Abstract: The rates of Bronsted-acid-catalyzed reactions of ethyl tert-butyl ether, tert-butanol, levoglucosan, 1,2-propanediol, fructose, cellobiose, and xylitol were measured in solvent mixtures of water with three polar aprotic cosolvents: γ-valerolactone; 1,4-dioxane; and tetrahydrofuran. As the water content of the solvent environment decreases, reactants with more hydroxyl groups have higher catalytic turnover rates for both hydrolysis and dehydration reactions. We present classical molecular dynamics simulations to explain these solvent effects in terms of three simulation-derived observables: (1) the extent of water enrichment in the local solvent domain of the reactant; (2) the average hydrogen bonding lifetime between water molecules and the reactant; and (3) the fraction of the reactant accessible surface area occupied by hydroxyl groups, all as a function of solvent composition. We develop a model, constituted by linear combinations of these three observables, that predicts experimentally determined rate constants as a function of solvent composition for the entire set of acid-catalyzed reactions.

TL;DR: It is shown that further increases in catalyst performance in polar aprotic solvents can be achieved through the addition of inorganic salts, specifically chlorides.

TL;DR: In this article, the authors performed reaction kinetics and mechanistic studies on lignin model compounds to understand the reaction mechanism and its sensitivity to variables in a continuous hydrogenolysis process using a Pd/C catalyst.

TL;DR: In this paper, the authors report the kinetics and selectivity of 1,2-propanediol dehydration in pure water and in aqueous mixtures of the polar aprotic cosolvents γ-valerolactone, 1,4-dioxane, tetrahydrofuran, N-methyl-2-pyrrolidone, tetramethylene sulfoxide, and dimethyl sulfoxide at 433 K.