Selective activation of peroxymonocarbonate over a Co/N-doped carbon catalyst for a 1O2-mediated oxidation process

Catalytic activation of oxidants to generate reactive oxygen species (ROS) is important for oxidation processes. In in-situ formed peroxymonocarbonate (HCO4-)-based oxidation systems, the selective catalytic activation of HCO4- and the subsequent generation of ROS have not been investigated. Herein, we synthesized a N-doped carbon- supported Co-based catalyst (Co/MA-2@C) and studied its selective catalysis in HCO4- activation. The decompositions of co-existing oxidants (HCO4- and H2O2), and the evaluation of ROS were studied, indicating that a greater quantity of free radicals, such as center dot OH and CO center dot 3, was generated through the selective activation of HCO4-. Optimizing the concentration ratio of HCO3- and H2O2 enhanced center dot OH yield from 11.9 % to 22.8 %. Achieving an equilibrium reaction between HCO3- and H2O2 prior to the successive catalytic activation of HCO4- further promoted center dot OH yield to 26.8 %. The HCO4--based oxidation system degraded 99 % of acid orange 7 with 1O2 (derived from center dot OH and CO center dot 3 ) as the responsible ROS. Catalytic mechanism suggested that low-valent Co served as catalytic active species to break the O-O bond of HCO4- via a N-doping promoted single electron transfer process. Ndoping increased Co0 species concentration, and induced the generation of surface oxygen-containing groups and positive charge of adjacent C that both benefited to the selective adsorption of HCO4-. This study, in terms of structure-activity relations of a catalyst, elucidates the catalytic activation of co-existing oxidants.