Revealing low-temperature reaction mechanism of cobalt-doped CeO2 catalyst for catalytic removal of methyl mercaptan

Methyl mercaptan (CH 3 SH) is notorious for global air pollution owing to its odorous characteristics and adverse health effects. Although CeO 2 is currently regarded as a promising catalyst for CH 3 SH decomposition, the high conversion temperature followed by high energy consumption is still a bottleneck. Herein, the cobalt-doped CeO 2 catalyst was synthesized by a facile one-pot preparation strategy and successfully reduces the decomposition temperature from 450 to 250 °C. Further studies demonstrate that the excellent low-temperature catalytic activity of Co 0.6 Ce 0.4 O 2– σ is attributed to its abundant oxygen vacancies and reactive oxygen species. Oxygen vacancies promote the adsorption and dissociation of CH 3 SH, while reactive oxygen species facilitate the decomposition of CH 3 SH. Moreover, Co acts as a sacrificial agent for the adsorption of sulfur species in CH 3 SH, while Ce is responsible for the adsorption and activation of CH 3 SH as the active metal phase. Furthermore, the migration and transformation mechanism of CH 3 SH on the surface of Co 0.6 Ce 0.4 O 2– σ was determined via in situ diffuse reflectance infrared Fourier transform spectra ( in situ -DRIFTS). This work provides a new strategy to synthesize high-performance catalysts for decomposing sulfur-containing volatile organic compounds (VOCs) at low temperatures, which is beneficial to decreasing the energy consumption.