物理化学学报 >> 1993, Vol. 9 >> Issue (02): 187-192.doi: 10.3866/PKU.WHXB19930209

研究论文 上一篇    下一篇

V2O5在硅胶表面的分散及助剂K2SO4作用的研究

赵璧英; 王秋霞; 唐有祺   

  1. 北京大学物理化学研究所,北京 100871
  • 收稿日期:1991-11-11 修回日期:1992-05-16 发布日期:1993-04-15
  • 通讯作者: 赵璧英

Study on Dispersion of V2O5 on Surface of SiO2 and the Effect of Promoter K2SO4

Zhao Bi-Ying; Wang Qiu-Xia; Tang You-Qi   

  1. Institute of Physical Chemistry, Peking University, Beijing 100871
  • Received:1991-11-11 Revised:1992-05-16 Published:1993-04-15
  • Contact: Zhao Bi-Ying

摘要: 用原位XRD方法证明V_2O_5能在硅胶表面自发分散, 但所需温度较高. 水汽对V_2O_5的分散有一定的阻碍作用. K_2SO_4可显著加快V_2O_5在SiO_2表面的分散速度, 并能降低V_2O_5/SiO_2的表面酸性. 被中和的主要是强酸位. 这可能是K_2SO_4能够改善V_2O_5/SiO_2催化剂在选择氧化反应中选择性的重要原因之一.

关键词: V2O5/SiO2催化剂, 表面分散, K2SO4助剂

Abstract: It has been shown by in situ XRD that V_2O_5 can disperse spontaneously onto the surface of silica gel, but the dispersion temperature is relatively high. The presence of H_2O vapour inhibits the dispersion of V_2O_5 to a certain extent, The dispersion process of V_2O_5 onto the surface of silica gel can be accelerated by using K_2SO_4 as an additive. The surface acidity of V_2O_5/SiO_2 is quite strong. However, K_2SO_4 can suppress the acidity by neutralizing strong acid sites. This may be one of the important reasons why K_2SO_4 can improve the selectivity of V_2O_5/SiO_2 for many selective oxidations.

Key words: V2O5/SiO2 catalyst, Dispersion on surface, K2SO4 promoter