化学液相沉积改性Hβ分子筛催化剂催化甲基萘与甲醇烷基化反应

Methylation of Methylnaphthalene with Methanol on Hβ Molecular Sieve Catalysts Modified by Chemical Liquid Deposition Method

研究了用正硅酸乙酯化学液相沉积改性的Hβ分子筛催化剂催化甲基萘与甲醇的烷基化制备2,6-二甲基萘(2,6-DMN)的反应。考察正硅酸乙酯沉积条件对Hβ分子筛催化剂的骨架结构、比表面积、表面酸性及对甲基萘与甲醇的烷基化反应催化性能的影响。优化了溶剂种类、沉积时间、正硅酸乙酯沉积量等改性条件。实验结果表明,改性后的Hβ分子筛的骨架结构基本不变,比表面积减小,表面酸中心数减少;对甲基萘与甲醇的烷基化反应,改性后的Hβ分子筛催化剂的催化活性下降,而择形性能明显提高。

Methylation of methylnaphthalene with methanol for preparing 2,6-dimethylnaphthalene(2,6-DMN)on Hβ molecular sieve catalysts modified by Si(OC_2H_5)_4 chemical liquid deposition was studied.Effects of deposition conditions on framework structure,specific surface area,surface acidicity of modified Hβ molecular sieves,methylation conversion and selectivity of 2,6-DMN were investigated.Modified conditions,namely solvent type,deposition time,loading amount of Si(OC_2H_5)_4 were optimized.Framework structure after modification of Hβ molecular sieve was basically unchanged,but specific surface area and number of acids sites on it decreased.Catalytic activity of modified Hβ molecular sieve catalyst decreased while shape-selectivity increased obviously.