激光促进甲醇在氧化物上的表面反应

LASER STIMULATED SURFACE REACTION OF METHANOL ON OXIDE COMPOUNDS

运用红外光谱 (IR)、程序升温脱附 (TPD)技术 ,对甲醇吸附在氧化物SiO2 、γ Al2 O3 和MgO表面所形成的反应体系进行了红外振动结构和化学吸附形态分析 ,并引入 10 5 2cm- 1 激光 ,研究了上述体系的激光促进表面反应(LSSR)规律。结果表明 :所选固体材料能够明显促进甲醇光促分解反应 ,室温条件下即可在SiO2 上达到 40 5 %的转化率 ;另外与甲醇吸附强度和吸附量相比 ,反应体系的振动结构对LSSR效率起着更为重要的作用 ,SiO2 因能够较好地吸收、传送激光能量而具有比γ Al2 O3 和MgO更好的促进反应性能。最后 。

Methanol is selected as a model reactant to carry out laser stimulated surface reaction(LSSR), where SiO 2, γ Al 2O 3 and MgO were used as surface materials and a TEA CO 2 laser generator is adopted as the light source The vibration structures of the CH 3OH ad oxide systems were discussed basing on IR test It is also showed that methanol is adsorbed on the surfaces only as molecular state, which was also confirmed by TPD test Furthermore, it was also proved that γ Al 2O 3 can adsorb more methanol than SiO 2 and MgO The results of reaction experiments showed that methanol decomposing reaction can take place at room temperature, by activating C-O bond of methanol with laser at 1?052?cm -1 , and this reaction can be enhanced in large scales by introducing the oxide materials The largest methanol conversion 40 51% was secured on SiO 2 surface, whose ability of adsorbing methanol is not the strongest, which is attribute to the fact that SiO 2 can absorb and transfer the 1?052?cm -1 laser energy to adsorbed methanol molecules more efficiently than γ Al 2O 3 and MgO It was then concluded that the vibration structure of the reacting system should be the most important factor to influence the LSSR process According to the experimental results, the LSSR mechanism of methanol is presented