Selective Incorporation of Iron Sites into MFI Zeolite Framework by One-Pot Synthesis

Developing highly efficient methods to selectively incorporate active metal sites into the zeolite framework is crucial for the large-scale utilization of metal-zeolites in various catalytic reactions including alkane conversion. Herein, ferrous gluconate is developed as an efficient metal precursor to embed Fe atoms into the MFI siliceous zeolite framework. The crystallization time and Si/Fe ratio are systematically investigated. It is revealed that the ferrous gluconate is well soluble and stable under alkaline conditions, allowing ferrous gluconate to participate in the whole crystallization course of zeolite. Multiple characterizations demonstrate that the tetrahedrally coordinated Fe atoms are selectively incorporated into the MFI siliceous zeolite framework (Fe-MFI). A catalytic test in propane dehydrogenation shows that the optimized Fe-MFI zeolite possesses high activity, propylene selectivity, and durability. This study opens an efficient strategy to incorporate isolated Fe atoms into the zeolite framework.