Oxidative dehydrogenation of propane with nitrous oxide over Fe-ZSM-5 prepared by grafting: Characterization and performance

• Fe-MFI prepared by grafting as active catalyst for propane dehydrogenation with nitrous oxide.
• Transformation of iron sites in Fe-MFI and enhancement in dehydrogenation activity upon high-temperature calcinations.
• Extra-framework Fe–O–Al species as active sites for propane dehydrogenation with nitrous oxide.

Iron-zeolites with well-defined extra-framework iron species were prepared via organometallic chemistry grafting route, i.e. the surface reaction between ferrocene and Brønsted acid sites in zeolites, and the calcined iron-zeolites were studied as catalysts for N2O-mediated oxidative dehydrogenation of propane to propylene. The framework structures of zeolite hosts and the calcination temperatures showed great impact on the catalytic performances. Fe-ZSM-5 calcined at 1073 K exhibited the highest activity for N2O-mediated propane oxidative dehydrogenation and a maximal initial propylene yield of ca. 30% can be obtained at a reaction temperature of 748 K (after time-on-stream of 15 min). A transformation of iron sites in Fe-ZSM-5 upon high-temperature calcination was well established based on the spectroscopic characterization results from UV–vis, H2-TPR, EPR and FTIR of NO adsorption. According to the correlation between catalytic activity and iron sites, extra-framework Fe–O–Al species are proposed to be the preferred active sites for N2O-mediated oxidative dehydrogenation of propane.

Figure optionsDownload high-quality image (150 K)Download as PowerPoint slide