Immobilization of crystalline Fe2O3 nanoparticles over SiO2 for creating an active and stable catalyst: A demand for high temperature sulfuric acid decomposition

To address the issues of catalytic activity and stability of the promising Fe2O3/SiO2 catalyst for sulfuric acid decomposition, Fe2O3 was immobilized on SiO2 support by polyol, solvothermal and wet-impregnation methods and examined. The different methods yielded catalysts with varying crystal structure, porosity, morphology and redox properties which were investigated by XRD, Modssbauer spectroscopy, N-2-BET surface area, SAXS, ED-XRF, HR-TEM, TPR/O and XPS techniques. The effect of the properties on the activity and stability was evaluated in a fixed-bed reactor and a structure-activity correlation was established. Above 750 degrees C the catalytic activity followed the order polyol > wet impregnation similar to solvothermal. Stability of the sample prepared by polyol method was ascertained by 100 h experimental run at 800 degrees C. The higher activity and stability of the Fe2O3/SiO2 catalyst (polyol) is ascribed to the development of crystalline alpha-Fe2O3 dispersed phase, higher pore confinement, better support-active phase interactions and higher degree of reduction.

Automated summary

The study focused on addressing the issues of catalytic activity and stability of the Fe2O3/SiO2 catalyst using different preparation methods. The catalysts showed varying properties and the sample prepared by polyol method exhibited higher activity and stability.