Details

Autor(en) / Beteiligte

• Xiong, Shangchao
• Zhang, Kai
• Xu, Zhenghao
• Ou, Hongjun
• Zheng, Yuanyuan
• Li, Xi
• Peng, Yue
• Luo, Xubiao
• Li, Junhua

Titel

Enhancing Ozone catalytic decomposition through acid treatment of α-MnO2 for improved activity and humidity resistance

Ist Teil von

• Journal of environmental sciences (China), 2025-03, Vol.149, p.35-45

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2025

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• •α-MnO2 synthesized by grinding method shows excellent O3 decomposition activity.•Nitric acid treatment further improves the activity and water resistance of α-MnO2.•Nitric acid treatment enhances the content of O vacancies and Brønsted acid sites.•O3 adsorbed on O vacancies forms H-bond with the protonic H of Brønsted acid sites.•The H-bond accelerates the cleavage of O3 to O2. Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts. Here the α-MnO2 catalyst treated with 0.1M nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid. Besides the increases in surface area and lattice dislocation, the improved activity can be due to relatively higher Mn valence on the surface and newly-formed Brønsted acid sites adjacent to oxygen vacancies. The remnant nitro species deposited on the catalyst by nitric acid treatment is ideal hydrophobic groups at ambient conditions. The decomposition route is also proposed based on the DRIFTS and DFT calculations: ozone is facile to adsorb on the oxygen vacancy, and the protonic H of Brønsted acid sites bonds to the terminal oxygen of ozone to accelerate its cleavage to O2, reducing the reaction energy barrier of O2 desorption. [Display omitted]