The Initial Reactions of HaPO4 and NaH2PO4 Supported on Silica： A Joint Experimental and Theoretical Study  

二氧化硅负载型磷酸及磷酸二氢钠初始反应：试验和理论研究

作　　者：张志强[1] 屈一新[1] 王水[1] 王际东[1] 

机构地区：[1]北京化工大学化学工程学院,北京市生物加工过程重点实验室,北京100029

出　　处：《Chinese Journal of Chemical Physics》2009年第3期315-321,340,共8页化学物理学报（英文）

摘　　要：A combination of X-ray powder diffraction, thermogravimetric analysis, diffuse reflection infrared Fourier transform, and ^31p magic-angle spinning nuclear magnetic resonance techniques with density function computation was used to elucidate the products and mecha- nism of the reactions among silica, H3PO4, and NaH2PO4 during the preparation of silica supported H3PO4 and NaH2PO4 catalysts. The spectral test results indicate that besides polyphosphoric acid, silicon phosphates on silica supported H3PO4 are also formed. On silica supported NaH2PO4 only sodium polyphosphates are present. Density functional theory （DFT） simulations indicate that in the initial stage, reaction of H3PO4 with silanol groups on the silica support is more favorable than that between H3PO4 itself. In contrast, dimerization and trimerization of NaH2PO4 are predicted to be the predominant initial reactions for the silica supported NaH2PO4 catalyst.

关 键 词：H3PO4 NaH2PO4 CONDENSATION SILICA DFT 

分 类 号：O643.12[理学—物理化学] TS264.3[理学—化学]