Membrane catalysts for partial hydrogenation of 1,3-butadiene: catalytic properties of palladium nanoclusters synthesized within diblock copolymer films

Palladium nanoclusters were synthesized within microphase-separated diblock copolymer films of [MTD]113[Pd(CpN)PA]50 (MTD=methyltetracyclododecene, CpN=endo-2-(cyclopentadienylmethyl)norborn-5-ene, PA=η3-1-phenylallyl). The organometallic repeat units were reduced by exposing the films to hydrogen at 100°C, leading to the formation of nearly monodisperse palladium nanoclusters. TEM was used to measure the cluster size. The nanocomposite films were active and selective catalysts for the gas phase hydrogenation of 1,3-butadiene. Selectivity for butenes was improved by lowering the hydrogen partial pressure, and lower temperature favored formation of 1-butene over 2-butenes.