Mn Deposited Co3O4 Hollow Microcages Derived from ZIF-67 for Efficient CO Low-temperature Oxidation

Graphical A hollow microcage structured CoMn- x catalyst was synthesized by the template method. In which abundant CO 3+ as well as surface reactive oxygen species on the surface of the CoMn-2 catalyst enabled it to exhibit extremely high catalytic activity for CO under space velocity 36,000 mL g cat −1 h −1 , being able to completely eliminate CO at 80 °C and maintain stable catalytic activity for up to 100 h. Cost-effective and highly efficient catalyst is a promising way for the removal of CO in automotive exhaust purification. Herein, a series of novel self-assembled CoMn bimetallic catalysts with hollow microcage structure have been prepared through zeolitic imidazole framework (ZIF-67) assisted method followed by direct pyrolysis in static air. Both the Mn loading and the unique hollow microcage structure play important roles in CO low-temperature oxidation, and the highest catalytic activity is obtained for CoMn-2 catalyst, which presents T 100 (temperature of 100 % CO conversion) at 80 °C. Through a systematic series of experiments, we further demonstrate that our catalysts’ superior catalytic performance arises from small particle size, high surface active oxygen content and Co 3+ /(Co 2+ +Co 3+ ) ratio. Such configuration of catalysts will pave the way for new strategies to design noble-free high-performance catalysts for CO low-temperature oxidation.