Combined computational-experimental study of Ru(0)-catalyzed Guerbet reaction

The homologation of bioethanol to higher alcohols by means of the Guerbet reaction is a promising way to obtain biofuels. Herein, we present an efficient ruthenium-catalyzed process and a detailed investigation of the reaction mechanism using a combined experimental-computational approach. Density functional theory calculations of the free energy profiles are corroborated by designed experiments. Microkinetic simulations are performed based on the calculated energies, providing good agreement with experimental observations of the time-evolving ethanol conversion and product distribution. Analysis of the kinetics network elucidates the key steps governing the conversion and selectivity of the Guerbet process, pointing out the unexpected role of the molecular hydrogen evolution step and suggesting strategies to design new catalysts for the Guerbet reaction.