In this study, Fe-containing silica catalysts (0.27–0.43 wt % Fe) were synthesized and tested for a stable methane to olefins, aromatics, and hydrogen (MTOAH) reaction. The catalysts, prepared using various methods and melt-fused at 1700 °C, showed increased densities due to Fe species in the SiO2 mixtures. Characterization techniques such as H2-TPR, TEM, and XAS revealed that partially reduced iron oxide (Fe3O4) was present in cristobalite (CRS) in the melt-fused catalysts. The Fe©CRS catalyst, derived from fayalite and quartz, demonstrated high resistance to sintering and coke deposition at 1020 °C. It had a 40% higher activation energy for coke formation than for methane consumption between 1000 and 1040 °C. The catalyst was more selective in producing C2, C3–C5 olefins, and aromatics compared to pure CRS and other Fe catalysts. It showed stable activity and low coke selectivity over 50 hours of reaction. EXAFS profiles indicated the formation of highly dispersed Fe carbide with Fe–Si coordination, and electronic structure calculations suggested these sites favored methyl radical formation and resisted coke. Under optimized conditions, the Fe©CRS catalyst achieved 6.9–5.8% methane conversion and 86.2% C2 selectivity for 100 hours with 50% H2 cofeeding at 1080 °C.-Scientific Journal cover by scapiens
[Scientific Journal cover design] Low-Thermal-Budget Fluorite-Structure Ferroelectrics for Future Electronic Device Applications
In article number 2100028, Jiyoung Kim, Si Joon Kim, and their team review key factors involved in developing fluorite-structure ferroelectrics
