Effect of surface treatment technique on properties and performance of Na2WO4‐TiO2‐MnOx/SiO2 for oxidative coupling of methane

BACKGROUND Oxidative coupling of methane (OCM) is a promising catalytic process for the conversion of methane to higher‐valued hydrocarbons (C2+). In this study, Na2WO4‐TiO2‐MnOx/SiO2 (NWTM) catalysts were obtained by various treatment techniques, including conventional calcine (CC, 800 °C), cold plasma (CP, 7 kV, 1 Hz), microwave radiation (MW, 800 °C), and electron beam radiation (EB, 4000 kGy), with no surface treatment (WT) as a benchmark method. RESULTS The results showed substantial differences in catalytic performance. The catalyst prepared by the cold plasma method provided the highest performance in the activity (20.91% C2+ yield with 48.04% C2+ selectivity and 43.52% CH4 conversion) at the early stage of testing (1–4 h). CONCLUSION However, the catalyst prepared by microwave radiation achieved the most stable active phases for the 24‐h testing period and yielded the highest C2+ for a five‐cycle reusability test. The catalyst prepared by electron beam radiation was found to have the lowest C2+ activity due to the poor distribution of the active elements. © 2021 Society of Chemical Industry (SCI).