关键词: 甲烷, 部分氧化, 甲醇, 负载杂多酸, 激光促进表面反应

Abstract: Solid materials PMo₁₂ and PMo₁₂ /CaF₂ were prepared, and the surface structure, chemisorption to methane and the behavior of LSSRfor the materials have been investigated by using IR, XRD, BETand laser stimulated surface reaction techniques. With different amounts of PMo₁₂, the distribution of PMo₁₂ can be controlled from less than one layer to multi layer on the surface of CaF₂. There exist Lewis base sites O_2- in MoOand Mo—O—Mo bonds as well as Lewis acid site —Mo ⁶⁺ — on the solid surfaces. Methane can be adsorbed on the surface MoOand Mo—O—Mo bonds with the molecular adsorption state, and the adsorption amount on Mo=Obond is greater. With 960 cm^-1 laser to excite the surface Mo=Obond, the partial oxidation of methane occurred obviously at normal pressure and 200 ℃. Methanol is the direct product of methane oxidation, while HCHO, CH₃OCH₃ and hydrocarbons are the products of methanol reacted continuously on the solid surface. As CaF₂ doesn't adsorb 960 cm^-1 laser, PMo₁₂ /CaF₂ can utilize the laser energy more efficiently than that of PMo₁₂. According to the characterization and reaction results, a mechanism of LSSRfor methane partial oxidation to methanol is given.

Key words: Methane, Partial oxidation, Methanol, Heteropoly acid, Laser stimulated surface reaction