XRD研究负载型氧化物催化剂活性组份的非晶态量和存在状态

Study on the Non-Crystallinic Quantity and States of Active Component of Supported Oxide Catalysts

应用X光射线相定量分析法测定了NiO负载在γ-Al_2O_3、SiO_2、TiO_2,经EDTA和CH_3NO_2改性的γ-Al_2O_3等载体上的分散阈值(非晶相活性组份量)。分析了影响XRD相定量测定准确度的主要因素,提出了消除或减少择优取向、微吸收效应、峰重叠(载体的干扰)、制样及峰型弥散等因素对定量测定干扰的方法,讨论了XRD方法测定非晶相量的可靠性。扩大了XRD技术在催化研究中的应用。同时对不同载体对活性组份状态的影响进行了讨论。

In this paper, the maximun dispersion of NiO on various supports including γ-Al_2O_3, SiO_2, TiO_2, EDTA-γ-Al_2O_3, CH_3NO_2-γ-Al_2O_3 is determined by using the method of X-ray diffraction quantitative phase analysis. The main factors such as preferred orientation of the crystallite, micro-absorption, reduplication of diffraction peaks, mixing degree of samples etc. which influence the accuracy of determination and the reliability of phase quantitative analysis are discussed. Several effective meatus for minimizing the influences of the above factors on phase quantitative determination, and for raising the accuracy have been proposed, Meanwhile the influence of the supports on the states of the active component is also discussed.