Oxygen reduction reaction (ORR) is one of the most important reactions in biological life process for energy conversion. In nature, copper metalloenzymes is one of the catalysts managing the dioxygen reduction, in which Cu ions show interconversion between Cu(II) and Cu(I) states to reduce oxygen. We design a Cu-containing metallopolymer of poly(2-hydroxy-3-dipicolylamino) propyl methacrylate capped with pyrene (Pyrene-PGMADPA). The dipocolylamine ligands in the metallopolymer act as the binding sites for Cu(II) ions, known as type-2 Cu sites. The Cu-metallopolymer can be mixed with the conductive carbon to prepare a hybrid electrocatalyst using π-π interaction between pyrene groups and the carbon support. As-prepared hybrid catalyst of Cu-metallopolymer on the carbon support (CuPoly-C) is an efficient bio-inspired catalyst for ORR. The results showed an onset potential of 0.93 V (vs. RHE), and an overpotential of 0.56 V based on half wave potentials (E1/2) at pH 13. At 0.6 V vs RHE, the CuPoly-C showed a current density of 0.26 mA cm-2, which is 3 times higher than that of polymer on carbon support without Cu(II) centers (0.08 mA cm-2). The kinetic study indicates a 2e- reduction of O2 when the potential is lower than 0.6 V. The rational design of bio-inspired polymer catalysts can be also used to guide the synthesis of catalysts mimicking different metal catalytical centers.

Bioinspired oxygen reduction using metallopolymers containing multi-Cu(II) active sites

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.