Nitrogen-coordinated cobalt embedded in hollow carbon polyhedron for catalytic ozonation of odor CH3SH at ambient temperature

Abstract

Metal − organic framework (MOF) derived carbon-based nanocatalysts have received great attention in environmental remediation applications. Herein, a hollow carbon polyhedron with nitrogen-coordinated cobalt embedded has been synthesized by thermal transformation of the core–shell structure ZIF-8@ZIF-67 (marked as ZIF-8@ZIF-67-C). Remarkably, the ZIF-8@ZIF-67-C catalyst could remove almost 98% of CH3SH after running for 60 min, exceeding the reported values (about 30 times higher than that of commercial MnO2 catalysts). Elimination performance experimental results demonstrate that ZIF-8@ZIF-67-C has better anti-interference ability and anti-toxicity properties. The excellent catalytic performance can be attributed to the following facts: unique structure, high conductivity, abundant hierarchical porous structure, and accessible active sites. Theoretical calculation reveals the mechanism is that the Co-N electron bridge promotes Co nanoparticles adsorb O3, providing electrons to O3 and producing 1O2 to further oxidize CH3SH into CO2/SO42−. Also, the ZIF-8@ZIF-67-C catalyst supported on Al2O3 still shows excellent catalytic activity and durability, which deepened the practical application. This work provides a strategy for the development of MOF-on-MOF-derived metal/carbon hybrid materials in environmental applications.