H-Zr-MCM-48的合成及其正庚烷异构性能

Synthesis of H-Zr-MCM-48 and Its Application in n-Heptane Isomerization

通过水热法成功合成了锆掺杂的MCM-48(Zr-MCM-48)介孔材料,并用离子交换制得H-Zr-MCM-48催化剂。采用X射线衍射(XRD)、透射电镜(TEM)、氮气吸附-脱附等测试手段对样品进行表征。结果表明,所合成的Zr-MCM-48及H-Zr-MCM-48仍保持立方有序介孔结构,H-Zr-MCM-48催化剂的酸性及催化稳定性均有所提高。在正庚烷异构化探针反应中,同等反应条件(锆/硅摩尔比为0.02、反应温度为260℃、反应时间为130min)下,与Zr-MCM-48相比,H-Zr-MCM-48对正庚烷异构化反应的催化性能更好,转化率和选择性分别达到44.6%和94.5%。相对较高的多支链异庚烷产物比例表明,所合成的H-Zr-MCM-48催化剂对于烷烃异构化有良好的应用潜力。

Zirconium incorporated MCM-48 mesoporous materials were synthesized by hydrothermal method.And the H-Zr-MCM-48 catalyst was prepared by ion exchanging method.The sample was characterized by various methods including X-ray diffraction,transmission electron microscope,N2 adsorption-desorption,and catalytically evaluated by n-heptane isomerization.These results reveal that the synthesized Zr-MCM-48 and H-Zr-MCM-48 still maintain a cubic ordered mesoporous structure.The acidity and stability of the H-Zr-MCM-48 catalyst is also enhanced.H-Zr-MCM-48 exhibits excellent catalytic performance in n-heptane isomerization. Under the same reaction conditions,compared with Zr-MCM-48,the conversion and the selectivity in H-Zr-MCM-48 system are 44.6% and 94.5%,respectively,with molar ratio of Zr to Si of 0.02,the reaction temperature of 260℃and the reaction time of 130 min.The high selectivity of multi-branched i-heptane products indicates that the synthesized H-Zr-MCM-48 catalyst has good application potential in alkane isomerization.