Efficient catalytic degradation of toluene at a readily prepared Mn-Cu catalyst: Catalytic performance and reaction pathway

• Published in: Journal of colloid and interface science Vol. 591; pp. 396 - 408
• Main Authors: Li, Jian-Rong, Zhang, Wan-Peng, Li, Chang, He, Chi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2021
• Subjects: acetaldehyde; acetic acid; acetone; benzaldehyde; benzene; benzoquinones; benzyl alcohol; catalysts; catalytic activity; coprecipitation; durability; ethanol; formaldehyde; Hydrothermal-redox; methanol; mineralization; Mn-Cu bimetallic oxides; oxidation; oxygen; phenol; PTR-MS; Spinel; temperature; toluene; Toluene oxidation; Mn-Cu bimetallic oxides; Toluene oxidation; Spinel; PTR-MS; Hydrothermal-redox
• ISSN: 0021-9797; 1095-7103; 1095-7103
• DOI: 10.1016/j.jcis.2021.01.096

[Display omitted] Fabricating of economical transitional metal oxide-based materials with satisfied low-temperature catalytic performance and application perspective is still a challenge in deep degradation of VOCs. Here, Mn-Cu bimetallic oxides were facilely prepared by one-step hydrothermal-redox method, which displayed much higher catalytic activity in toluene oxidation than those synthesized by hydrolysis-driven redox-precipitation or co-precipitation approach. It is shown that the lattice defect and oxygen vacancy concentration over prepared materials can be tuned by controlling Cu/Mn molar ratio. Amongst, spinel structured MnCu0.5 exhibited the highest catalytic activity, superior durability and water resistance in toluene total oxidation owing to abundant surface adsorbed oxygen species, excellent low-temperature reducibility, and high amounts of Cu+ and Mn3+. In detail, the reaction rate of MnCu0.5 was over 9.0 times higher than that of MnCu0.75, MnCu0.75-P and MnCu0.75-H2O2 at relative low temperature of 210 °C. The cyclic redox process with easier oxygen species mobility played a key role in the catalytic oxidation of toluene. Typical reaction intermediates as benzyl alcohol, benzaldehyde, benzene, phenol, and benzoquinone could be detected by PTR-MS, which further decomposed to acetone, ethanol, ketone, acetic acid, methanol, formaldehyde and acetaldehyde species by ring opening before total mineralization.