Nanosized ERI-type aluminophosphate
was prepared by the calcination
of a precursor material (denoted as ECNU-38P) synthesized using 1,1,6,6-tetramethyl-1,6-diazacyclododecane-1,6-diium
hydroxide (TDDH) as a structure-directing agent. The structure of
ECNU-38P is related to ERI topology but exhibits a highly disordered
manner and contains both four- and six-coordinated Al atoms. In situ XRD patterns revealed a rarely reported temperature-induced
three-dimensional (3D)-to-3D structural transformation from ECNU-38P
to the ordered ERI-type ECNU-38 zeolite at 573–623 K. Nanosized
ERI-type silicoaluminophosphate Si-ECNU-38 was also obtained by introducing
Si atoms into the synthetic system of ECNU-38P. The catalytic performance
of ERI-type silicoaluminophosphates in the methanol-to-olefin (MTO)
reaction was revealed to be highly related to the crystal sizes.