Highly active and reusable palladium nanoparticle catalyst stabilized by polydimethylsiloxane for hydrogenation of aromatic compounds in supercritical carbon dioxide

Abstract

This study describes a hydrogenation method for degrading polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in supercritical carbon dioxide catalyzed by palladium nanoparticles stabilized in polydimethylsiloxane (Pd/PDMS). The process of synthesizing metal nanoparticles embedded in PDMS polymers involves the preparation of a homogenous mixture of metal salt, silicone elastomer, and a curing agent, followed by hydrogen reduction. PCBs and PAHs can be effectively hydrogenated to saturated hydrocarbons with greater than 99% efficiency in an hour under 200atm of CO2 containing 10atm of H2 at 313K using Pd/PDMS catalysts. The proposed Pd/PDMS catalysts can be reused without losing their activity and are significantly more active than commercial catalysts and a previously reported Pd nanoparticle catalyst stabilized in high-density polyethylene.