论文部分内容阅读
本文应用X-光衍射,电子能谱等技术考察了氟在γ-Al_2O_3及NiW/γ-Al_2O_3催化剂中的存在形态,发现氟的存在形态受催化剂制备条件、组成等多种因素制约。本文认为,氟主要以两种形式存在:表面基及AlFi(OH)_3-i(i=1～3),当氟含量较低时,主要以表面基的形式存在,对催化剂脱氮性能起作用的正是这一部分氟。红外光谱研究发现:γ-Al_2O_3经氟处理后在其表面引入了Br(?)nsted酸中心,同时Lewis酸中心的数量减少,强度增加,负载活性组分后在催化剂表面也引入了Br(?)nsted酸中心。
In this paper, the existence of fluorine in γ-Al 2 O 3 and NiW / γ-Al 2 O 3 catalysts was investigated by X-ray diffraction and electron spectroscopy. It was found that the existence of fluorine was restricted by many factors such as catalyst preparation conditions and composition. It is believed that fluorine exists mainly in two forms: surface group and AlFi (OH) 3-i (i = 1-3). When fluorine content is low, it mainly exists as surface group, It is this part of the role of fluorine. The results of FTIR showed that Br (?) Nsted acid sites were introduced into the surface of γ-Al 2 O 3 by fluorine treatment, while the number of Lewis acid sites decreased and the intensity increased. Br (? nsted acid centers.