Rapid removal of methyl mercaptan using Mn-coated columnar activated carbon catalyst at ambient temperature

Abstract

The Mn-coated activated carbon catalysts were prepared via an in situ impregnation and redox method for the abatement of methyl mercaptan (CH₃SH). The results demonstrated that the sample containing 20 wt% Mn displayed a superior removal efficiency for CH₃SH, achieving nearly complete conversion under mild conditions of 25 °C, 100 ppm for 60 min in a 30 L stainless steel test chamber. By integrating the characterization and experimental results, the excellent catalytic performance could be attributed to the enhanced acid–base properties deriving from the Mn-coating, which not only influenced the chemical environment of the activated carbon surface, but also promoted CH₃SH adsorption and association. Furthermore, the catalysts displayed remarkable durability with only slight deactivation even after prolonged storage or exposure to extreme high temperature and humidity, suggesting a promising pathway for practical applications in indoor air purification. The gas chromatography–mass spectrometry (GC–MS) results indicated that dimethyldisulfide (CH₃SSCH₃) was the main product. This provides a promising design for the elimination of CH₃SH with high performance, feasibility, and prolonged longevity using Mn-coated activated carbon catalysts.