Pickering emulsion enhanced interfacial catalysis under Taylor flow in a microchannel reactor

There are still technical challenges associated with surface fouling and clogging in microchannels when conducting multiphase catalytic reactions involving solid particles. In this study, a Pickering emulsion was employed to enhance the oxidation of benzyl alcohol (BNOH) catalyzed by Pd/SiO2 nanoparticles under Taylor flow in a microchannel reactor. The reaction characteristics of benzyl alcohol/water Pickering emulsion in a microchannel reactor were studied experimentally. The characteristic results showed that the O/W Picking emulsion system was superior to the W/O Picking emulsion system for the catalytic oxidation reaction. The influences of a wide range of operational variables were characterized on the conversion of reactants and the selectivity of the desired product. The optimized reaction conditions included: reaction temperature 403 K, CB 5 wt%, O2/BNOH (mol/mol) 0.76 and tube length 8 m. Under the optimal operating conditions, the conversion of BNOH and the selectivity of benzaldehyde were found to be 86.53% and 99.79%, respectively. In addition, the interfacial transport-reaction mechanism in Pickering emulsions under Taylor flow in microchannels was proposed from the perspective of multiphase mass transfer. This development provided significant insights and guiding for effectively performing multiphase catalytic reactions involving solid catalyst particles in microchannel reactors.