Isomorphous substitution of 3- and 4-valent heteroelements for Si is a practical approach to develop a zeolite catalyst with high activity and selectivity. Different nature of incorporated heteroatoms within the framework of the host zeolites makes the crystallization process challenging and time-consuming.
Herein, we developed a practical approach to synthesize a set of heteroelement-substituted chabazites in proton form (M-CHA[H], M = B, Al, Ga, and Ti) using the pure silica CHA (Si-CHA) as the crystal growth seeds. The time required to obtain highly crystalline M-CHA[H] was significantly reduced in comparison with existing procedures.
The incorporated heteroatoms were proved to be located in the framework of CHA using FTIR and UV-Vis spectroscopy. Thus, the proposed approach has been demonstrated as a facile and fast way to synthesize the isomorphously substituted CHA in proton form.