Synthesis of Hexagonally Ordered Super-Microporous Silicas, Using Conventional Alkyltrimethylammonium Bromide, as Adsorbents for Water Adsorption Heat-Pump Systems

Super-microporous silicas with an ordered hexagonal structure were synthesized under dilute conditions using a conventional alkyltrimethylammonium halide as a template. The d100 of the super-microporous silicas was approximately 23 A. The pore diameter of one of the obtained samples, determined by an argon adsorption measurement, was 16.7 A. This material adsorbed water vapor with a P/P0 value higher than 0.29, while desorbing it with a P/P0 value lower than 0.14. It can be inferred that this super-microporous silica is suitable as an adsorbent for an adsorption heat-pump system.