摘要
以沉淀法合成了FePO4 、AlPO4 和Fe0 .5Al0 .5PO4 三种固体表面材料。采用XRD、IR和TPR方法对各材料进行了表征。以分子探针IR和TPD方法考察了甲烷在固体表面上的吸附性能。以固体表面键激发模式研究了激光促进甲烷直接氧化合成甲醇的表面反应规律。结果表明 ,FePO4 、AlPO4 和Fe0 .5Al0 .5PO4 均具有均一的晶态结构 ,其晶格氧的活泼性顺序为Fe0 .5Al0 .5PO4 >FePO4 >AlPO4 。在 1 0 0℃以上时 ,CH4 能够以分子态吸附于固体表面PO键上 ,各表面材料的吸附能力也遵循Fe0 .5Al0 .5PO4 >FePO4 >AlPO4 的规律。在 1 0 0～ 30 0℃范围内 ,采用 1 0 83cm- 1的激光激发固体表面PO键 ,CH4 直接氧化生成CH3OH的反应明显发生且CH3OH的选择性在 80 %以上。CH转化率的大小与固体表面材料晶格氧活泼性及其对CH4 的吸附能力有关。用 1 0 0 0cm- 1和 91 0cm- 1的激光激发PO键 ,不能有效促进化学反应的发生 ,揭示了激光光能的有效吸收和传递是LSSR过程能否实现的关键因素。
Three solid surface materials FePO_4, AlPO_4 and Fe_0.5Al_0.5PO_4 were prepared by the dipping method.The surface structure, chemisorption of methane and LSSR properties of the surface materials have been investigated by the techniques of XRD, TPR, IR-TPD and laser stimulated surface reaction.All of the three surface materials have homogeneous crystal structure with oxygen activity Fe_0.5Al_0.5PO_4>FePO_4>AlPO_4.CH_4 can be adsorbed on surface PO bond to form molecular adsorption state at temperature higher than 100℃, and the adsorption ability of the three materials also follows the order Fe_0.5Al_0.5PO_4>FePO_4>AlPO_4.Using laser (1083cm^-1) to stimulate the surface PO bond, CH_4 partial oxidation to methanol carries on easily with methanol selectivity higher than 80% in the temperature range 100～300℃.The conversion of CH_4 depends on the lattice oxygen activity and CH_4 adsorption ability of the surface materials.With 1000 and laser (910cm^-1) to stimulate the surface PO bond of the surface materials at 200℃, the conversion of CH_4 is very low (<0.1%), which indicates laser energy adsorption and transfer are two important aspects to LSSR.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2000年第5期401-405,共5页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金!资助项目批准号 :2 97730 31
关键词
甲烷
甲醇
部分氧化
激光促进表面反应
磷酸盐
methane, methanol, partial oxidation, laser stimulated surface reaction, phosphate
