Metal-Organic Framework-Derived Hollow CoMn2O4 Nanocube Catalysts for Deep Toluene Oxidation

Designing unique nanostructures and components for catalysts can promote the deep catalytic degradation of volatile organic compounds into CO2. Herein, a pyrolysis strategy for MOF-based oxides (Mn-3[Co(CN)(6)](2)center dot nH(2)O) was employed to successfully synthesize oxygen vacancy-enriched Mn-Co spinel oxides with hollow nanocube structures (denoted as MOF-CMO/400). Compared with CoMn2O4 nanoparticles prepared by the traditional precipitation method, MOF-CMO/400 presented a T-90 of 209 degrees C for toluene catalytic oxidation, which was 38 degrees C lower than that of CoMn2O4 nanoparticles (247 degrees C). Especially in a high-temperature region, MOF-CMO/400 nanocubes possessed a narrower temperature range to achieve 100% toluene conversion than CoMn2O4 nanoparticles. The excellent catalytic activity of MOF-CMO/400 is mainly attributed to the three-dimensional hollow structure, more oxygen vacancy defects, longer Mn-O bonds, and abundant active oxygen species. Furthermore, MOF-CMO/400 nanocubes displayed good humidity resistance (above 5-10 vol % H2O). Therefore, the nanocatalyst with a distinctive structure and defects has great potential in industrial application for deep toluene oxidation.

Automated summary

In this study, oxygen vacancy-enriched Mn-Co spinel oxides with hollow nanocube structures were successfully synthesized using a pyrolysis strategy. The nanocubes exhibited excellent catalytic activity and a narrower temperature range for toluene conversion compared to CoMn2O4 nanoparticles. The unique structure, oxygen vacancy defects, longer Mn-O bonds, and abundant active oxygen species contributed to the superior catalytic performance of the nanocubes. Additionally, the nanocubes showed good humidity resistance.