FeTiO3: A low-cost and efficient photocatalytic mineral for sustainable NOx abatement
Jefferson E. Silveira, Vinícius G. Garcia, Luíza T. Pacheco, Wendel S. Paz, José A. Casas, Juan A. Zazo
Abstract
• FeTiO 3 is presented as a low-cost and effective photocatalyst for NOx removal in flue gases. • Demonstrated high photocatalytic efficiency in NO x abatement, even under low-temperature and high-humidity conditions. • Elucidation of the NO oxidation mechanism, with insights supported by both experimental data and DFT calculations. • FeTiO 3 offers a sustainable and scalable alternative to conventional NO x control technologies for pollution mitigation. This study investigates the potential of FeTiO 3 as a photocatalyst for the removal of nitrogen oxides (NO x ) from gas streams, a critical environmental and health concern. The photocatalytic activity of FeTiO 3 was evaluated across a range of operational parameters, with initial NO concentrations set from 5 to 50 ppmv and gas hourly space velocity (GHSV) values of 18, 36, and 54 h −1 . The findings demonstrate that FeTiO 3 effectively converts NO x , even at room temperature and under saturated atmosphere, with a clear correlation between the photocatalytic removal efficiency and both the initial NO concentration and GHSV. A rigorous mechanism for the photooxidation of NO to nitrate via NO 2 was proposed based on these experimental results and the surface characterization of raw and used ilmenite, corroborated by DFT calculations. These outcomes would allow widening the application of air pollution control strategies to flue gas with relatively low NO x concentration and low temperature, where other NO x control techniques show severe drawbacks. Therefore, this research contributes to the development of efficient and sustainable approaches for air quality improvement using photocatalytic systems.