Enhanced thermal stability and moisture toleration for toluene catalytic decomposition over MnCoOx supported hierarchical porous biochars with CeO2 encapsulation

• Published in: Journal of environmental chemical engineering Vol. 13; no. 2; p. 115493
• Main Authors: Jiang, Yun, Gao, Lei, Dai, Jianyong, Xie, Dong, Li, Caiting, Xiong, Huiyu, Zhang, Jiahao, Xu, Qing, Wang, Jiajie, Tan, Yuheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2025
• Subjects: Catalytic oxidation; Mn-Co composite oxides; Moisture toleration; Oxygen vacancy; Thermal stability; Moisture toleration; Catalytic oxidation; Mn-Co composite oxides; Thermal stability; Oxygen vacancy
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2025.115493

The thermal stability of carbon-based catalysts remains a tremendous obstacle that deters their practical applications under high temperature range. Herein, a battery of MnCoOx supported hierarchical porous biochars with CeO2 encapsulation (MnCo/CeO2@BAC) were facilely fabricated for toluene degradation. The strategy of CeO2 encapsulation can prevent biochars from high temperature damage and emerging hydrogen bonding with interfacial H2O, thereby strengthening the thermal stability and H2O resistance of catalysts. The intrinsic relationship between catalytic activities and their physicochemical features was systematically comprehended via diverse characterization techniques. 10 %Mn0.5Co0.5/CeO2@BAC manifested surpassing activity, outstanding mineralization rate, satisfactory thermal stability, and preeminent SO2 and H2O toleration at a broad temperature interval. The impacts of O2, SO2 and H2O on toluene purification over 10 %Mn0.5Co0.5/CeO2@BAC were delved, thereinto, SO2 and H2O exhibited prohibitive effects on toluene abatement, whereas O2 demonstrated stimulative influence on toluene elimination. In contrast to 10 %Mn/CeO2@BAC and 10 %Co/CeO2@BAC, 10 %Mn0.5Co0.5/CeO2@BAC rendered superior catalytic performance due to bimetallic cooperative effect, superior redox property, more oxygen vacancies and lattice defects, higher proportions of Mn4 + and Co3+, larger Oads/Olatt ratio and better metal oxide dispersion. Based on characterization results, chemically adsorbed oxygen dominated toluene adsorption and partial oxidation, while lattice oxygen was largely responsible for its deep oxidation. [Display omitted] •CeO2 encapsulating BAC could enhance the thermal stability and H2O and SO2 toleration of 10 %Mn0.5Co0.5/CeO2@BAC.•The cooperative effect of Mn and Co oxides facilitated oxygen vacancies formation and reactive oxygen species mobility.•The immanent relationship between the abatement performance and relevant structural property was comprehensively discerned.•The possible mechanism for toluene oxidation over 10 %Mn0.5Co0.5/CeO2@BAC were comprehended and proposed.