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The CuMn/ZSM-5 (CM/Z), CuMn/Beta (CM/B), and CuMn/SSZ-13 (CM/S) catalyst samples were prepared via an excess impregnation method to investigate the metal-support effect. The results show that the activity at 550 °C for NO direct decomposition follows the order of CM/Z (53.4%) > CM/B (49.2%) > CM/S (7.9%). The good activity and stability of CM/Z are attributed to a strong support effect including forming more active copper sites of the (Cu2+-O2--Cu2+)2+ and (Cu+-□-Cu+)2+ dimers, which have higher redox activity, capacity of oxygen mobility, and NO sorption capability. The competitive adsorption between NO and O 2 on the oxygen vacancy of dimers over CM/Z results in the activity decrease from 53.4% to 40.3% at 550 °C after adding 1 vol% O 2. The reaction mechanism over CM/Z was discussed based on the in situ DRIFT and isotopic (18O 2) experiments. Two NO adsorbs firstly on (Cu+-□-Cu+)2+ to form N 2 O, and N 2 O is activated to produce N 2 , followed by the NO adsorption on (Cu2+-O2--Cu2+)2+ to form nitrite and nitrate species and decomposition to NO and O 2. [Display omitted] ● The support effect of ZSM-5, Beta, and SSZ-13 supported CuMn is examined. ● CuMn/ZSM-5 exhibits a high NO to N 2 conversion of 53.4% at 550 °C. ● The intermediate species and competitive adsorption of NO and O 2 are discussed. ● The reaction pathways for NO direct decomposition are proposed. [ABSTRACT FROM AUTHOR]

• Ea of intermediate species is calculated during toluene oxidation. • Relationship between the activation energy of the overall and primitive reaction. • Transient response experiments of isotopically labeled oxygen. • M−K mechanism dominates in the oxidation of toluene. Catalytic properties of multiple metals deposited on TiO 2 nanoparticles were investigated in the oxidation of toluene. Isovolume impregnation method prepared the catalysts containing Cu, Mn, Ni, Co, and Fe deposited on TiO 2 , including CeO 2 and ZrO 2. The effects of loaded metal oxides on the structure and activity of initial catalysts were investigated using various characterization techniques. Toluene's removal efficiency and CO 2 selectivity in the catalyst system were classified as follows: CuCeZr/T > MnCeZr/T > NiCeZr/T > CoCeZr/T > FeCeZr/T. Presence of water vapor exhibits an inhibitory effect on the conversion of toluene, which diminishes at higher temperatures. One contribution of this paper is to obtain the oxidation pathway of toluene and the relationship between the activation energy of all-inclusive and elementary reactions based on the variation of infrared spectrum using Freeman-Carroll method. Another contribution is to clarify the share of Langmuir-Hinshelwood and Mars-van Krevelen mechanisms during the oxidation of toluene over CuCeZr/T catalyst by transient response experiments of isotopically labeled oxygen. These findings provide a feasible method for the design and synthesis of transition metal oxide catalysts for industrial applications. [ABSTRACT FROM AUTHOR]