国产航空煤油裂解催化剂Pt/ZrxTixAl1-2xO2的性能

采用共沉淀法制备了一系列Zr_xTi_xAl_1-2xO₂复合氧化物载体材料，考察了其作为裂解催化剂载体对航空煤油裂解反应的影响.?采用全自动吸附仪、X射线衍射、扫描电镜/能谱仪联用、NH₃-程序升温脱附等手段对催化剂进行了表征.?结果表明，当ZrO₂：TiO₂：Al₂O₃质量比为1：1：3时催化剂具有最大的比表面积和孔容；具有最强的表面酸性和最集中的强酸中心密度，且具有良好的再生功能.?实验结果表明，载体ZrO₂：TiO₂：Al₂O₃质量比为1：1：3时催化剂上650?℃裂解产气量较热裂解提高了2.1倍，700?℃时提高1.4倍.?另外，该系列载体材料经1000?℃焙烧5?h后，所制得的催化剂几乎失去了催化活性.

The performance of Pt/ZrxTixAl1-2xO2 as Kerosene cracking catalysts

Zr_xTi_xAl_1-2xO₂ composite oxides for use as supports were prepared by coprecipitation and assessed with regard to their catalytic performance during the kerosene cracking reaction. The catalysts were characterized by N₂ adsorption-desorption, scanning electron microscopy-energy dispersive spectrometry, X-ray diffraction, and temperature-programmed desorption (NH₃-TPD). The results showed that a support composed of ZrO₂:TiO₂:Al₂O₃ in the ratio of 1:1:3 exhibited the highest surface area and pore volume, and had the strongest surface acidity and highest acidic density. Energy dispersive spectroscopy results showed that catalysts from which carbon deposits were removed by heating under oxygen changed very little, and additional experimental data confirmed that these catalysts are readily regenerated while retaining their functionality. The gaseous reaction products produced over ZrO₂:TiO₂:Al₂O₃ (1:1:3)-supported Pt catalyst generated during catalytic cracking was 2.1 times and 1.4 times higher than that obtained with thermal cracking at 650 ℃ and 700 ℃, respectively. An examination of the catalytic performance of Pt catalyst supported on composite oxides calcined at 1000 ℃ for 5 h indicated that these materials lost much of their catalytic activity.