Oxidative Coupling of Methane over Na-W-Mn Catalysts Supported by Ti-Si Molecular Sieves
1. College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China;
2. Quzhou Research Institute, Zhejiang University, Quzhou 324000, China
Abstract A series of Na-W-Mn-loaded catalysts with different supports (Ti-SBA-15, TS-1, Ti-MWW and SiO2) were prepared and tested in the oxidative coupling of methane at different reaction temperatures. The catalysts were characterized by X-ray diffraction (XRD), N2 physical adsorption, temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The results showed that Na2WO4 and Mn2O3 played a vital role in the reaction. The addition of Ti effectively activates methane was at lower temperature, and improved the migration of active components from the bulk phase to the surface of catalysts. Moreover, Ti-SBA-15 also increased the concentration of surface active phases and surface active oxygen species. Therefore, Na-W-Mn/Ti-SBA-15 showed the better activity, with 22% of CH4 conversion and 63% of C2 selectivity at a low temperature of 720 ℃.
