Ag-promoted Cr/MnO catalyst for catalytic oxidation of low-concentration formaldehyde at room temperature

• Published in: Physical chemistry chemical physics : PCCP Vol. 25; no. 14; pp. 1155 - 1165
• Main Authors: Duan, Chaomin, Meng, Mianwu, Huang, Huang, Wang, Heng, Ding, Hua, Zhang, Qi
• Format: Journal Article
• Published: 05.04.2023
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d3cp00557g

As one of the significant pollutants in indoor air, formaldehyde (HCHO) has attracted increasing attention due to its negative effects on human health. Thus, to reduce formaldehyde pollution, herein, an Ag-promoted Cr/MnO 2 catalyst (Ag/Cr/MnO 2 ) was obtained via a hydrothermal-calcination method, which was employed for the catalytic oxidation of low-concentration indoor HCHO (∼1 ppm) at room temperature. The Ag/Cr/MnO 2 catalyst eliminated approximately 98.62% HCHO within 14 h and maintained a high removal efficiency continuously under the dynamic test conditions. Furthermore, the catalyst exhibited good recycling stability and outstanding activity in a humid environment. Different characterization techniques were utilized to determine the physicochemical properties that contribute to improving the catalytic performance. The Ag substance contained metallic Ag (Ag 0 ) as the main component and some Ag 2 O, and the Ag 0 particles provided ample active sites for the catalytic oxidation of HCHO. Besides, the incorporation of Ag increased the reducibility of the catalyst and the content of Mn 4+ , Cr 6+ and oxygen vacancies. The abundant active sites, high reducibility, rich Mn 4+ , Cr 6+ , oxygen vacancies, and surface lattice oxygen species, and the powerful interaction between Cr/MnO 2 and Ag were the reasons for the splendid catalytic capability for HCHO by the Ag/Cr/MnO 2 catalyst. In conclusion, the Ag/Cr/MnO 2 catalyst can be a promising catalyst to degrade HCHO with practical application significance. An Ag/Cr/MnO 2 catalyst was prepared via a simple hydrothermal-calcination method. Compared with the Cr/MnO 2 catalyst, the comprehensive performance of the Ag/Cr/MnO 2 catalyst was greatly improved, which has potential for industrial applications.