To improve the physicochemical properties of CHA-type zeolites, we synthesized a CHA-type titanosilicate zeolite (Ti-CHA) with titanium instead of aluminum incorporated into its framework. Ti-CHA zeolites with various Si/Ti ratios were directly prepared by a 24-h hydrothermal reactions with the use of colloidal silica and titanium oxide as Si and Ti sources, respectively. A peak, assignable to isolated tetrahedrally coordinated Ti species, was clearly observed at ca. 220 nm in the UV–vis spectra of the Ti-CHA zeolite, confirming that titanium was incorporated into the zeolite framework. The effects of titanium content in the CHA zeolite on the thermal and acid stabilities were investigated. No changes were observed in the crystallinity, BET surface area, and micropore volume of a Ti-CHA zeolite with a Si/Ti ratio of 347, even after thermal treatment at 1150 °C. Furthermore, no changes were observed in the crystallinity of Ti-CHA zeolites with Si/Ti ratios of 45–347, after treatment with aqueous hydrochloric acid at 75 °C for 5 days. The amount of water adsorbed by the Ti-CHA zeolite with a Si/Ti ratio of 347 was lower than those of high-silica CHA-type zeolite with Si/Al = 10 (Al-CHA zeolite) and pure-silica CHA-type zeolite (Si-CHA zeolite).

为了提高CHA型沸石的理化性质，我们合成了钛代替铝并入其骨架的CHA型钛硅酸盐沸石（Ti-CHA）。通过分别使用胶体二氧化硅和氧化钛分别作为Si和Ti源的24小时水热反应直接制备具有各种Si / Ti比的Ti-CHA沸石。大约在一个峰值处清楚地观察到一个峰，该峰可归因于分离的四面体配位的Ti物种。Ti-CHA沸石的UV-vis光谱为220 nm，证实钛已掺入沸石骨架中。研究了CHA沸石中钛含量对热稳定性和酸稳定性的影响。Si / Ti比为347的Ti-CHA沸石的结晶度，BET表面积和微孔体积未见变化，即使在1150°C下进行热处理后。此外，在75°C的盐酸水溶液中处理5天后，Si / Ti比为45-347的Ti-CHA沸石的结晶度未见变化。Si / Ti比为347的Ti-CHA沸石吸附的水量低于Si / Al = 10的高二氧化硅CHA型沸石（Al-CHA沸石）和纯二氧化硅CHA型沸石沸石（Si-CHA沸石）。