摘要
自从Parry提出用吡啶吸附红外光谱研究固体表面酸性质后,已被广泛应用于沸石表面酸性研究.关于沸石表面L酸的产生以及能否可逆地转换为B酸仍有不同的看法.β沸石有与八面沸石相似的孔径尺寸和吸附能力,比八面沸石有更高的硅铝比。由于它优异的催化性能而受到重视.我们用吡啶吸附红外光谱研究Hβ沸石表面酸性时,发现了一些新的现象,这不仅使我们了解Hβ沸石表面酸性的特点,也将有助于深化对沸石表面L酸的认识.
Lewis acid on HB zeolite after pyridine adsorption has been studied by infrared speetroscopy. The spectrum of pyridine coordinately bonded to positive silicon ion on 3 zeolite is markedly different from that , of pyridine, coordinately bonded to alumina and from that of hydrogen bonded pyridine. This permits to differentiate L(A1), L(Si) and -SiOH on HB zeolite.. There are L(A1) and L(Si) which are created by positive -silicon ion HB zeolite. The reason of the formation of positive silicon ion and the problem of the eonverson of B acid into L acid or of L acid to B acid on HB zeolite were discussed.
基金
中国科学院自然科学基金
