高比表面氧化镁催化剂的制备及性能

Synthesis of Magnesium Oxide with High Specific Surface and Its Catalytic Performance on the Double Bond Isomerization of Butene

通过对商业重质氧化镁进行有机酸改性,得到了一种高比表面的固体碱氧化镁催化剂。X射线衍射,比表面积,扫描电镜,程序升温脱附等表征研究显示,与商业重质氧化镁催化剂相比,该催化剂结晶度较低,晶粒较小,同时比表面积显著增大,表面碱性位增多,有强碱性位出现。该催化剂用于催化1-丁烯双键异构制2-丁烯反应的结果显示,该催化剂的稳定性相比商业重质氧化镁催化剂大大提高。由此推断新的制备方法使催化剂表面产生更多缺陷位,提供了更多碱性中心,从而延长了活性位的流失时间,提高了稳定性。

A kind of magnesium oxide catalyst with higher specific surface area was prepared through the modifying of the commercial heavy magnesium oxide by organic acid, and was characterized by X-ray diffraction, BET, scanning electron microscope and CO2 temperature programmed desorption. It is found that the catalyst has poorer crystallization, smaller crystal size, higher surface area and more basic sites comparing with the hydrolyzed magnesium oxide. The MgO catalyst was applied to catalysis the double bond isomerization of butane-1 to butane-2, and the result showed that the stability of the MgO was much better than that of the hydrolyzed magnesium oxide. It may be inferred that the modifying by the organic acid gives more chemical structure defects to the surface of the magnesium oxide, and the chemical structure defects are the source of the basic sites which favor the stability.