Zeolites are porous, crystalline materials widely used in industry for catalysis and separation. The article describes a new way to create a new zeolite by capturing it as a transition phase during the controlled breakdown of another zeolite. Typically, zeolites are made under harsh conditions, and many potentially useful structures are lost because they decompose or become amorphous before they can be isolated. This study focused on a parent zeolite called IWV, which contains special building blocks (double-four-ring units rich in germanium) prone to structure changes.
By carefully adjusting the chemical composition, crystal size, and treatment conditions of IWV, it was possible to slow down the transformation process and "catch" a new, highly crystalline intermediate zeolite named IPC-20. This was achieved by using a seed-assisted crystallization method and then gently transforming the material in a water–alcohol system. We solved the structure of IPC-20 using advanced three-dimensional electron diffraction techniques.
This research shows that it is possible to isolate new zeolite structures by stopping the transformation process at just the right moment, rather than letting it run to completion. The discovery of IPC-20 opens new possibilities for making and studying previously inaccessible zeolites, which could lead to new materials for industrial and environmental applications. Our team contributed to the work by performing electron diffraction experiments and providing the structure analysis of the newly prepared zeolite, which was crucial to validating the success of the procedure.
Figure:. Evolution of the IWV structure during transformation under acidic conditions. XRD patterns of IWV-1 and IWV-2 samples treated with 0.1 M HCl for different times (a) and subsequently calcined at 450 °C (b). XRD patterns of IWV-1 and IWV-2 samples treated with 12 M HCl for different times (c) and subsequently calcined at 450 °C (d). The images in the right part of each section show an enlarged segment of the corresponding diffraction pattern in the range of 2θ 5−10°. Two lines in (d) represent the positions of the (200) reflection estimated for IWV-derived daughter zeolites containing different linkers, “−S4R−” or “−O− , between the layers.