Selective catalytic activation of peroxymonocarbonate over a Co/Al2O3 catalyst

We assessed the selective catalytic performance of Co/Al2O3 in activating HCO4- for tetracycline degradation by studying the activation of oxidants and the generation of reactive oxygen species. Co/Al2O3 exhibited high catalytic selectivity towards HCO4- in the presence of H2O2, achieving a H2O2 utilization efficiency of 74.9 % for the production of center dot OH. The Co/Al2O3-catalyzed HCO4--based system oxidized 89.2 % of tetracycline primarily through center dot OH and CO3 center dot- generated from HCO4- activation, while center dot O-2 and O-1(2) played minor roles in degradation. Low-valent cobalt species served as catalytic active sites for HCO4- activation. Abundant oxygen vacancies on Co/Al2O3 accelerated the electron transfer, forming a local electron-rich region that preferentially adsorbed electrophilic HCO4- and provided additional active sites for HCO4- activation. Furthermore, the increased Lewis acid sites assisted HCO4- activation by stabilizing the leaving carbonate groups. This work offers insights into the structure-activity relations of catalysts for the selective catalytic activation of HCO4-.