Reverse Water Gas Shift Reaction at Low Temperatures via Fe ₃ C Using α-Fe ₂ O ₃ /Sugar Cane Bagasse Waste-Derived Silica Catalysts

The reverse water gas shift reaction (RWGS) is a favorable process for CO2 mitigation, which generates CO and H2O by hydrogenation of CO2. In this study, we have synthesized silica nanomaterials derived from sugar cane bagasse (SCBS) loaded with α-Fe2O3 to achieve effective performance in the RWGS reaction. Here, we utilize the precipitation and wet impregnation methods to produce an α-Fe2O3/SCBS catalyst for the low-temperature RWGS reaction with a 5–15 wt % α-Fe2O3 weight loading. At lower temperatures, this catalyst demonstrated significant CO2 conversions, along with excellent CO selectivity. The catalytic activity was found to be promising, with CO2 conversion ranging from around 26% to 43% and CO selectivity from 94% to 99% under 0.1 MPa pressure and at temperatures between 300 and 650 °C, using a reactant mixture of CO2:H2:N2 = 1:3:3 gas flow volume ratio over the 10% α-Fe2O3/SCBS catalyst. The synthesized catalysts were tested using various methods, including X-ray diffraction (XRD), small-angle XRD, N2 physisorption isotherms, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, micro-Raman spectra, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, and thermogravimetric analysis. This work provides valuable insights into the development of silica catalysts derived from sugar cane bagasse waste, which can be applied in various catalytic reactions beyond the RWGS process.