模拟硅铝催化剂上表面酸的研究(Ⅱ)——B酸存在的基本形式及硅铝比对B酸酸性的影响

A Study of Surface Acid on Mimic Silica-Alumina Catalyst(Ⅱ)-The Basic states of Bronsted Acid and the Influence of Silicon-Aluminium Ratio on Bronsted Acdity

用EHMO方法对无定形硅铝催化剂上表面酸进行模拟计算,研究B酸存在的基本形式及硅铝比对B酸酸性的影响。结果表明氧化铝含量对B酸酸性有很大影响,Al—O—Al结构的形成是造成B酸强度下降的根本原因。计算结果与B酸酸量的实验结果符合。

By applying EHMOmethod,a series of mimic calculations have been performed for the surface acid of Silica-Alumina catalyst,the basic states of Bronsted acid and the influence of Silica-Alumina ratio on Bronsted acidity have been studied.The calculations from different states of Bronsted acid show that the content of Aluminium in catalyst have a great influence upon the Dronsted acidity,and the forming of Al-O-Al structure is the essential reason for marked decrease of Bronsted acid strength.The results from theoretical calculations are in accordance with the experimental results of measurements of Bronsted acid.