Photodeposited Pd nanoparticle catalysts supported on photoactivated TiO2 nanofibers

Pd nanoparticle catalysts supported on photoactive titania nanofibers were investigated and evaluated with respect to model C-C coupling reactions. Titania nanofibers were prepared via the electrospinning technique, followed by in situ formation of the Pd nanoparticles catalyst on the TiO2 support. Pd nanoparticles of between 2 and 5 nm were successfully stabilized on the surface of electrospun nanofibers which had diameters between 150 +/- 50 nm. The new catalyst was found to have increased surface area and improved catalytic functions compared to commercially available materials or other Pd-TiO2 catalysts produced by different modes of synthesis. The activity and selectivity of 0.05 mol%Pd-TiO2 catalyst in the Heck reaction has been investigated with a careful look into the nature of starting materials and products under varying conditions of temperature, solvent and base. The catalyst was found to be highly active under air atmosphere with reaction temperatures of up to 160 degrees C. Optimized reaction conditions resulted in a 98% yield of trans-stilbene for the iodobenzene-styrene system with a TOF value of 7.85 min(-1). (C) 2011 Elsevier B.V. All rights reserved.