One-Step “Green” Synthesis of Pd Nanoparticles of Controlled Size and Their Catalytic Activity for Trichloroethene Hydrodechlorination

We present here a straightforward, one-step “green” approach for preparing Pd nanoparticles of controlled size and size distribution. The new catalysts were synthesized using a low-cost, biocompatible cellulose, sodium carboxymethyl cellulose (CMC), as a stabilizer and ascorbic acid as a reducing agent at temperatures ranging from 22 to 95 °C. The mean size and polydispersivity (expressed as standard deviation, SD) of the Pd nanoparticles was exponentially reduced by increasing the preparation temperature from 22 to 95 °C. At 95 °C, nearly monodisperse Pd nanoparticles were obtained with a mean diameter of 3.6 nm (SD = 0.5 nm). The Pd nanoparticles exhibited high catalytic reactivity when tested for hydrodechlorination of trichloroethene in the presence of H2. The observed pseudofirst-order reaction rate constant, kobs, was up to 692 L g−1 min−1, which is comparable to the Pd nanoparticles synthesized per the conventional borohydride reduction method. This new approach not only offers a simple way to mani...