Selective hydrogenation of 2-methyl-3-butyn-2-ol over Pd-nanoparticles stabilized in hypercrosslinked polystyrene: Solvent effect

Selective hydrogenation of 2-methyl-3-butyn-2-ol (MBY) to 2-methyl-3-butene-2-ol (MBE) over Pd supported on hypercrosslinked polystyrene was studied in polar (ethanol, isopropanol, water) and non-polar (cyclohexane, toluene, octane, hexane, heptane and m-xylene) solvents. The catalytic activity and selectivity were found to be strongly affected by solvent properties such as dipole moment and dielectric constant, but cannot be explained by solvent polarity only. Hydrogen solubility and solvent-catalyst interaction also influential factors. The catalyst activity decreases in the series: alcohols > cyclohexane > water/ethanol mixture > octane >= hexane >= xylene > toluene > heptane. The highest values of MBE selectivity of 99.6% and 98.7% at 95% MBY conversion were obtained in toluene and in ethanol, respectively. (C) 2014 Elsevier B.V. All rights reserved.