A team of researchers propose to develop granular activated carbon supported bimetal catalysts that integrate both physic-sorption and catalytic decomposition capabilities to achieve sustainable water treatment. The objective of the proposed project is to design and fabricate a novel class of granular activated carbon-supported palladium-metal (bimetal) catalysts that provides rapid contaminant degradation without accumulation of problematic by-products or significant susceptibility to poisoning (loss of catalytic activity) by common components of natural water.
This project takes advantage of the fact that catalytic hydrodehalogenation and hydrodeoxygenation by palladium (Pd) and Pd-based bimetal catalysts are capable of transforming various classes of organic contaminants to harmless products, this proposed research is focused on developing Pd-M bimetal catalysts where M represents gold (Au), copper (Cu), and indium (In) to achieve catalytic reductive transformation of priority drinking water contaminants such as halogenated organics, oxyanions, and nitrosamines. The PIs preliminary results show that the types of catalysts proposed to study can produce very rapid hydrodehalogenation of trichloroethene as well as hydrogenation of other model contaminants. In the proposed research, a green chemistry synthesis process will be developed. The link between catalyst structure and performance will be systematically investigated with catalysts designed to test specific catalytic mechanisms. Structures of Pd-M hybridized with both perfect graphene and defect-rich graphene in place of granular activated carbon will be modeled to determine the optimal surface structures, charge transfer mechanisms, electronic properties, and energetic distributions. The kinetics of contaminant reduction by such catalysts will be systematically quantified and a practical but rigorous kinetic model will be developed to compare these types of catalysts across a broad range of conditions. The sensitivity of these catalysts to inactivation by known poisons of noble metal catalysts (e.g., sulfide and chloride) common in water treatment will be evaluated and considered in optimization of the catalyst designs. In addition to advancing the technology of water treatment by catalytic hydrogenation processes, this proposed research will contribute to the training of new researchers and practitioners in the field. The PIS will reach out to water service professionals through a series of planned workshops at Clackamas Community College, which has a strong training program for water treatment engineers. Outreach activities to the general public for the demonstration of the sustainable water treatment through collaboration with the Oregon Museum of Science & Industry, a local leader in informal education, are also planned. Furthermore, we are committed to recruiting minority and female graduate students to participate in this proposed research.
