Catalytic polymeric membranes with palladium nanoparticle/multi-wall carbon nanotubes as hierarchical nanofillers: preparation, characterization and application

In this study, incorporation of Palladium nanoparticles into the membrane matrix using hierarchical nanostructures is reported as a novel approach to prepare catalytic polymeric membranes (CPMs). CMPs are prepared through a phase inversion method by loading of palladium nanoparticles decorated multi-wall carbon nanotubes (Pd-MWCNTs) with three different concentrations (0.1 %, 0.5 % and 1 wt%) in polysulfone/t-BA-EDA grafted polysulfone matrix. The PdMWCNTs impregnated PSf/PSf-g-P(t-BA-EDA) membranes are thoroughly characterized using TEM and XRD. SEM, TGA and DSC analyses were also performed to evaluate the effect of the Pd-MWCNTs on themorphology and thermal properties of catalytic membranes. The developed membranes are applied in a flow-through mode and showed excellent catalytic activities for selective oxidation of different alcohols to the corresponding aldehydes or ketones at solvent-free conditions. It was found that the reactivity and reusability of this catalytic membranes containing Pd-MWCNT were better than the conventional catalytic membranes containing free Pd nanoparticles. Catalytic membrane containing 1 % of Pd-MWCNT showed the highest reaction conversion (> 98%) in 5th cycle for benzyl alcohol oxidation. Moreover, 100 % aldehyde and ketone selectivity were observed for all the catalytic membrane samples.