Nanosheet-state cobalt-manganese oxide with multifarious active regions derived from oxidation-etching of metal organic framework precursor for catalytic combustion of toluene

Jinggang Zhao; Peifen Wang; Changlin Liu; Qiang Zhao; Junli Wang; Lei Shi; Guangwen Xu; Abuliti Abudula; Guoqing Guan

doi:10.1016/j.jcis.2022.08.187

Nanosheet-state cobalt-manganese oxide with multifarious active regions derived from oxidation-etching of metal organic framework precursor for catalytic combustion of toluene

J Colloid Interface Sci. 2023 Jan;629(Pt A):706-722. doi: 10.1016/j.jcis.2022.08.187. Epub 2022 Sep 5.

Authors

Jinggang Zhao¹, Peifen Wang², Changlin Liu¹, Qiang Zhao³, Junli Wang³, Lei Shi⁴, Guangwen Xu⁴, Abuliti Abudula¹, Guoqing Guan⁵

Affiliations

¹ Graduate School of Science and Technology, Hirosaki University, 1-Bunkyocho, Hirosaki 036-8560, Japan.
² Graduate School of Science and Technology, Hirosaki University, 1-Bunkyocho, Hirosaki 036-8560, Japan; Department of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China.
³ School of Chemistry and Environmental Engineering, Shanxi Datong University, Datong 037009, PR China.
⁴ Key Laboratory on Resources Chemicals and Materials of Ministry of Education, Shenyang University of Chemical Technology, Shenyang 110142, China.
⁵ Graduate School of Science and Technology, Hirosaki University, 1-Bunkyocho, Hirosaki 036-8560, Japan; Energy Conversion Engineering Laboratory, Institute of Regional Innovation (IRI), Hirosaki University, 3-Bunkyocho, Hirosaki 036-8560, Japan. Electronic address: guan@hirosaki-u.ac.jp.

PMID: 36099840
DOI: 10.1016/j.jcis.2022.08.187

Abstract

For the first time, a nanosheet-state CoMnx mixed oxide with multifarious active regions was synthesized by oxidation-etching assembly of metal organic framework (MOF) precursor and applied for catalytic combustion of toluene at low temperatures. The obtained optimum catalyst denoted as CoMn6 showed excellent performance, which achieved 90% conversion of 1,000 ppm toluene under a weight hourly space velocity (WHSV) of 60,000 mL/(g·h) at 219 °C. While, it also exhibited long-term stability with strong water resistance property. The characterizations of physicochemical properties indicated that the oxidation-etching assembly process built an abundant mesoporous structure in the CoMnx catalyst, which greatly increased the specific surface area (SSA). Especially, potassium permanganate as oxidant and manganese source led to uniform dispersion and assembling of cobalt atoms, which caused the generation of low-crystallinity CoMnx mixed oxide with abundant dislocations, vacancies, phase interfaces and amorphous structures, resulting in excellent low-temperature reducibility, outstanding lattice oxygen mobility and abundant active species such as Mn³⁺, Co³⁺ and adsorbed oxygen species. Density functional theory (DFT) calculations demonstrated that gaseous oxygen with the longer bond length (1.406 Å) and stronger adsorption energy (-4.443 eV) could be adsorbed and activated well on the MnCo₂O_4.5 (311) plane, which is beneficial for the toluene oxidation. In situ diffuse reflectance infrared spectroscopy (DRIFTS) technique was applied to track the intermediates of toluene combustion under different atmospheres, which further deduced the contributions of different active regions and oxidation mechanism over the CoMnx catalyst. The present facile strategy of oxidation-etching assembly of the MOF precursor for the creating of novel catalyst with high performance could be applied in a wide variety of materials besides VOC combustion catalysts.

Keywords: Catalytic combustion of VOCs; Metal organic framework precursor; Mixed metal oxide catalysts; Oxidation-etching assembly strategy; VOC oxidation mechanism.