摘要
利用电子衍射几何构图法确定固体磷酸催化剂中活性相正磷酸硅(Si_3(PO_4)_4)属于三角晶系。其晶格参数a_r=b_r=c_r=9.26(?),α=50°。确定焦磷酸硅(SiP_2O_7)为单斜晶系。其晶格参数a=4.7,b=12.0,c=7.6(?),β=91°。两种活性相的结晶形态明显不同。正磷酸硅呈规则六边形片晶。片晶面的法线为C_h轴方向。焦磷酸硅具有棱柱状外形。棱平行于a方向。而b与c在棱柱的横截面内。
The method of geometric construction of reciprocal lattice plane from series of electron diffraction patterns has been used to study the crystal structure of silicon orthophosphate (Si_3 (PO_4)_4)and silicon diphosphate (SiP_2O_7). Both of them are active phases in the catalyst of solid phosphoric acid. The silicon orthophosphate belongs to trigonal system with lattice para- meters a=b=c=9.26A, α=50, and the silicon diphosphate belongs to monoclinic system with lattice parameters a=1.7, b=12.0, c=7.6(?)?, β=91°. The crystal morphology of these two active phases is apparently different each other. The silicon orthophosphate appears as hexagonal crystalline plate with its normal parallel the to direction of c_h axis. The silicon diphosphate is of prism shape. The axis of the prism parallel to the a axis. The b and C axes lie in the cross-section of the prism.
出处
《电子显微学报》
CAS
CSCD
1989年第1期1-5,共5页
Journal of Chinese Electron Microscopy Society
