Energetics of microporous materials
Energetics of microporous materials
复制标题
微孔材料的能量学
DOI：
10.1016/0022-3093(95)00392-4
复制
发表时间：
1995
影响因子：
3.5
通讯作者：
Mark E. Davis
中科院分区：
文献类型：
--
作者：
A. Navrotsky;I. Petrović;Yatao Hu;C. Chen;Mark E. Davis
一系列高硅沸石的生成热只比石英低8-14kJ/mol，与体积(骨架密度)的关系很弱，尽管这些参数有两个变化因素。几种孔径在3-5 nm范围内的介孔二氧化硅，其能量稳定性也仅比石英低14kJ/mol。因此，在微孔和介孔区域，能量似乎稳定在仅比石英不稳定的约14kJ/mol的值，气孔表现得像惰性第二相。类似的趋势也出现在AlPO4沸石和脱水的CaAl硅酸盐沸石上。这些数据表明，微孔材料的合成不受其能量学的限制，而是通过为其形成找到合适的动力学路径来进行。
The enthalpies of formation of a series of high-silica zeolites are only 8–14 kJ/mol less exothermic than that of quartz, with a very weak dependence on volume (framework density), despite a factor of two variation in those parameters. Several mesoporous silicas, with pore diameters in the range 3–5 nm, also are only 14 kJ/mol less stable energetically than quartz. Thus, in the microporous and mesoporous regime, the energy appears to level off at values only about 14 kJ/mol less stable than quartz, with the pores behaving energetically like an inert second phase. Similar trends are seen for AlPO4zeolites, and for a dehydrated CaAl silicate zeolite. These data suggest that the synthesis of microporous materials is not limited by their energetics but by finding appropriate kinetic pathways for their formation.