Sepiolite-Supported Manganese Oxide as an Efficient Catalyst for Formaldehyde Oxidation: Performance and Mechanism.

The current study involved the preparation of a number of MnO _x /Sep catalysts using the impregnation (MnO _x /Sep-I), hydrothermal (MnO _x /Sep-H), and precipitation (MnO _x /Sep-P) methods. The MnO _x /Sep catalysts that were produced were examined for their ability to catalytically oxidize formaldehyde (HCHO). Through the use of several technologies, including N ₂ adsorption-desorption, XRD, FTIR, TEM, H ₂ -TPR, O ₂ -TPD, CO ₂ -TPD, and XPS, the function of MnO _x in HCHO elimination was examined. The MnO _x /Sep-H combination was shown to have superior catalytic activities, outstanding cycle stability, and long-term activity. It was also able to perform complete HCHO conversion at 85 °C with a high GHSV of 6000 mL/(g·h) and 50% humidity. Large specific surface area and pore size, a widely dispersed active component, a high percentage of Mn ³⁺ species, and lattice oxygen concentration all suggested a potential reaction route for HCHO oxidation. This research produced a low-cost, highly effective catalyst for HCHO purification in indoor or industrial air environments.