CAJ | 학술논문

采用浸渍法制备了一系列钨负载量不同的W/SiO2/Al2O3催化剂.采用X射线衍射(XRD)、激光拉曼(Raman)光谱、紫外-可见(UV-Vis)光谱、氢气程序升温还原(H2-TPR)和氨程序升温脱附(NH3-TPD)等技术对催化剂进行了表征.实验结果表明：钨的负载量对催化剂上氧化钨物种的分散程度、还原性以及催化剂的酸性有非常重要的影响.对该类催化剂上1-丁烯自歧化反应进行了详细考察，结果表明：当钨的质量分数为6.0%时， W/SiO2/Al2O3催化剂表现出最佳的歧化活性和稳定性.原因在于6.0%的钨负载量可以使催化剂上氧化钨物种具有中等程度的分散性、合适的还原性，并且使催化剂具有一定程度的酸性，这些因素有利于在催化剂上形成烯烃歧化活性位.
채용침지법제비료일계렬오부재량불동적W/SiO2/Al2O3최화제.채용X사선연사(XRD)、격광랍만(Raman)광보、자외-가견(UV-Vis)광보、경기정서승온환원(H2-TPR)화안정서승온탈부(NH3-TPD)등기술대최화제진행료표정.실험결과표명：오적부재량대최화제상양화오물충적분산정도、환원성이급최화제적산성유비상중요적영향.대해류최화제상1-정희자기화반응진행료상세고찰，결과표명：당오적질량분수위6.0%시， W/SiO2/Al2O3최화제표현출최가적기화활성화은정성.원인재우6.0%적오부재량가이사최화제상양화오물충구유중등정도적분산성、합괄적환원성，병차사최화제구유일정정도적산성，저사인소유리우재최화제상형성희경기화활성위.
A series of W/SiO2/Al2O3 catalysts with various tungsten loadings were synthesized via the impregnation method. The as-synthesized catalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, H2 temperature-programmed reduction (H2-TPR), and NH3 temperature-programmed desorption (NH3-TPD). The results reveal that the tungsten loadings were crucial to the dispersion and reducibility of the tungsten oxide species and the acidity of catalysts. The catalytic performances were also investigated during the metathesis of 1-butene to propene. Amongst these catalysts, W/SiO2/Al2O3 with a tungsten mass fraction of 6.0%gave the highest activity and stability during the 1-butene metathesis reaction. The excel ent catalytic performance of the catalyst containing a tungsten mass fraction of 6.0%is attributed to its moderate dispersion, suitable reducibility of the WOx species and suitable acidity. We speculate that these factors are favorable for the formation of active centers for olefin metathesis.