一、概述当前,工业上常用的分子筛,是一类三维网状沸石,属结晶形的硅铝酸盐。通常具化学通式:Me_(x/n)[(AlO_2)_x(SiO_2)_y]·mH_2O其中:x/n——价数为 n 的金属阳离子 Me 的数目;m——结晶水的分子数。某些分子筛沸石在自然界就有存在形态,它们具有筛分分子的性能,故在半个世纪以前就有人称共为“分子筛”了。人们对于分子筛沸石的认识,是从天然沸石开始,进而人工合成。对于天然沸石的了解,约在二个世纪以前就着手了。但是本世纪卅年代才开始系统地研究 I. Overview At present, molecular sieves commonly used in industry are a type of three-dimensional reticulated zeolite which is a crystalline aluminosilicate. Usually with the general chemical formula: Me_ (x / n) [(AlO_2) _x (SiO_2) _y] · mH_2O where: x / n - the number of metal cation Me number n; m - the number of crystal water molecules . Some molecular sieve zeolite exists in nature, they have the properties of sieving molecules, so some people call it a “molecular sieve” half a century ago. People’s understanding of molecular sieve zeolite, is from the natural zeolite, and then synthetic. Understanding of natural zeolites started about two centuries ago. However, this century began to study systematically