Assessment of acid catalytic properties of ferrosilicate MFI zeolite by methanol-to-hydrocarbon conversion.

Four representative synthetic methods were employed to prepare Fe-containing siliceous MFI zeolites. The obtained Fe-MFI zeolites exhibited markedly different catalytic performances in the methanol-to-hydrocarbon (MTH) conversion reaction depending on the type of Fe incorporation within the siliceous framework. The catalytically active Brønsted acid sites were analyzed using pyridine adsorption experiments combined with Fourier transform infrared spectroscopy, providing characteristic signal intensities according to the acid-base interactions. Based on the MTH conversion results and acidity analyses, a suitable synthetic method was identified for the incorporation of Fe within the MFI zeolite framework. However, compared to other catalytic reactions, structural analyses by transmission electron microscopy, ultraviolet-visible spectroscopy, and X-ray absorption spectroscopy were much less conclusive.