Chabazite Zeolite Synthesis Using Inorganic Structure-Directing Agents

Zeolites are aluminosilicate crystals with nanopores commonly used as adsorbents and catalysts in industrial applications. My zeolite framework of interest is chabazite (CHA), which is heavily used in industry to break down NOx emissions. In industry, most of this CHA is produced using organic structure-directing agents, which can produce CHA at high yields but is extremely expensive to use, is very dangerous to the environment, and cannot be recovered after synthesis due to calcination. In previous studies, inorganic structure-directing agents like potassium cations have been used to synthesize CHA instead of the traditionally used organic compounds, but this approach often yields CHA in a mixture of other different zeolite frameworks. Another approach to this issue is to use a mixture of inorganic structure-directing agents like lithium, sodium, and potassium cations to help isolate fully crystalline CHA. In previous studies led by Dr. Rimer and Dr. Mintova, combinations of potassium and strontium cations, as well as combinations of sodium, potassium, and cesium cations, have been used to synthesize relatively pure CHA yields. Over the Fall 2022 semester, I have been working with the Rimer group at the University of Houston to synthesize CHA at high purities and yields and across various temperatures and time ranges using multiple combinations of lithium, sodium, and potassium cations.