Alkali-free siliceous CHA zeolites with a wide Si/Al ratio ranging from 11 to infinity have been synthesized in hydroxide and fluoride media using either N,N,N-Trimethyl-1-adamantammonium (TMAda), N,N,N-Dimethylethylcyclohexyl ammonium (DMECHA) cations, or a mixture thereof. TMAda, in combination with other low-cost organic templates, allowed the formation of pure silica CHA without any impurities in the synthesis gel with an H₂O/SiO₂ ratio of 3. Single-phase crystalline pure silica CHA was produced by DMECHA within a very narrow range of H₂O/SiO₂ ratio, and small deviations in the water content from this range led to the formation of a slightly less dense zeolite beta phase. Alkali-free siliceous CHA zeolites possessing a high crystallinity and a variety of particle sizes were successfully prepared for the first time using a low-cost DMECHA template, particularly by a direct interzeolite transformation of FAU zeolites having the same secondary building unit of double-6-rings (D6Rs). This makes DMECHA an attractive organic structure-directing agent (OSDA) for wide applications of CHA zeolites as catalysts and adsorbents.

使用N，N，N-三甲基-1-金刚烷铵（TMAda），N，N，N-二甲基乙基环己基醚在氢氧化物和氟化物介质中合成了Si / Al比范围从11到无穷大的无碱硅质CHA沸石。铵（DMECHA）阳离子或其混合物。TMAda与其他低成本有机模板的结合，可以在H ₂ O / SiO _2之比为3的情况下，在合成凝胶中形成不含任何杂质的纯二氧化硅CHA 。单相结晶纯二氧化硅CHA由DMECHA生产。 H ₂ O / SiO _2的范围非常狭窄比率和水含量偏离该范围的小偏差导致形成密度稍低的β沸石。首次使用低成本DMECHA模板成功地制备了具有高结晶度和多种粒径的无碱硅质CHA沸石，特别是通过将具有相同二级结构单位的FAU沸石直接进行沸石间转化而成功制备的。 -环（D6Rs）。这使得DMECHA成为有吸引力的有机结构导向剂（OSDA），可广泛应用于CHA沸石作为催化剂和吸附剂。