Solvent-free alcohol oxidation using paper-structured catalysts: Flow dynamics and reaction kinetics

Abstract

Paper-structured fibrous composites with micrometer-sized pores were prepared using a papermaking technique, followed by in situ synthesis of Pd nanoparticles in the paper matrix using a facile impregnation method. The Pd-containing paper-structured catalysts showed high catalytic activities in solvent-free benzyl alcohol oxidation in a flow reaction system. Highly selective oxidation was achieved using the porous paper-structured catalysts set inside a gas–liquid–solid multiphase reactor. Kinetic and mechanistic studies of various reactions showed that the catalytic activity and selectivity were associated with microfluidic behavior in the fiber-network pores. A uniform distribution of the liquid-phase substrate, i.e., benzyl alcohol, provided high catalytic activity. High selectivity for the oxidation pathways can be attributed to efficient gas–liquid–solid mass transfer toward the thin liquid layer formed at the interface between the alcohol and Pd catalyst inside the porous fiber networks.