Nanoarchitectonics of hollow Co3O4 through tannic acid etching of ZIF-67 for catalysis of toluene oxidation

Oxide catalysts obtained by derivatization of MOFs as precursors often have excellent results in the catalysis of VOCs. In this study, the Co3O4 catalysts obtained by pyrolysis after tannic acid etching using ZIF-67 as precursor showed excellent toluene catalytic activity. Among them, Co3O4 −1–15 showed the best catalytic activity with T90 = 219 °C (the conversion temperatures of 90 %), which was 20 °C lower than that of Co3O4 -O obtained by direct pyrolysis of ZIF-67. It also exhibits excellent stability and cyclic stability. After tannic acid treatment, Co3O4 −1–15 exposed higher surface Co3+ and Olatt (surface lattice oxygen) content, which were the key factors for its most outstanding catalytic activity. Lattice oxygen mobility and oxygen vacancies were also important factors affecting catalyst activity.