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Highlights: [•] Highly efficient Pd nanoparticles were facilely synthesized by precipitation followed by NaBH4 reduction. [•] Complete oxidation of HCHO was achieved at room temperature on the 0.1wt% Pd–TiO2. [•] The precipitated Pd shows strong capacity for generation and transfer of active oxygen. [•] Water vapor is essential to HCHO oxidation since it favors the transfer of oxygen. [ABSTRACT FROM AUTHOR]

The application of photocatalytic oxidation (PCO) in VOCs abatement is greatly limited by catalytic deactivation and inefficiency. In this study, mesoporous TiO 2 was prepared by a one-step hydrolysis method via varying the calcination temperature and used for photocatalytic oxidation of gaseous benzene. Results revealed that the calcination temperature significantly affects the structural properties and catalytic activity of TiO 2 . The fabricated mesoporous TiO 2 exhibited much better catalytic activity and stability towards benzene degradation compared to commercially-available TiO 2 (P25) which suffered from quick deactivation and low efficiency. The samples calcined at 400 °C showed a good mesoporous structure and superior capacity for benzene adsorption, which led to the best photocatalytic activity. VUV irradiation in the PCO process greatly enhanced benzene degradation and exhibited a benzene removal efficiency of 80% while it was less than 10% under UV irradiation. VUV photolysis and O 3 generated from VUV irradiation made a major contribution to benzene degradation in the VUV-PCO process. [ABSTRACT FROM AUTHOR]

Catalyst deactivation and secondary pollution are the critical issues challenging the traditional heterogeneous catalysis (gas-solid) methods for VOCs removal at room temperature. This process strongly depends on the available OH radicals. Because of the facile formation of OH radicals, H 2 O 2 -based advanced oxidation processes (AOPs) may facilitate VOCs removal. In this paper, UV/H 2 O 2 , for the first time, was employed to degrade continuous-flow gaseous toluene in batch system with comparison to UV/Fenton and Fenton process. UV/H 2 O 2 process was identified to moderately generate OH radicals and yielded removal efficiency higher than 80% without any loss while it gradually declined to 32% and 45% within 120 min in the Fenton and UV/Fenton process, respectively. No emission of gaseous intermediates was identified at the outlet in all the AOPs. Most of the removed toluene was oxidized into CO 2 in the UV/H 2 O 2 process, however, many organic intermediates were generated in the solution of Fenton and UV/Fenton process. The superior performance of UV/H 2 O 2 process was mainly ascribed to the continuous formation of OH. This study demonstrates that UV/H 2 O 2 process can be applied as an efficient and environment-benign technology for VOCs treatment. [ABSTRACT FROM AUTHOR]