Low-temperature selective catalytic reduction of NOx with NH3 over in-situ grown MnOx-Fe2O3/TiO2/Ti monolithic catalyst

Abstract

The design and synthesis of highly efficient and low-temperature NOx reduction catalysts with long-term stability and good water resistance still remain a challenge in the field of gas catalysis. In this work, we demonstrated the integration of MnOx-Fe2O3/TiO2/Ti monolithic catalysts on flexible Ti mesh through plasma electrolytic oxidation technology, associated with hydrothermal reaction, and chemical bath deposition methods. The in-situ grown TiO2 nanosheet supports hold a very strong substrate adhesion with Ti mesh, and provide ideal nucleation sites for the following deposition of high density of MnOx-Fe2O3 active components. The brush-like nanostructure morphology of active MnOx-Fe2O3 catalysts enables the complete adsorption and reaction of gas molecules on the catalyst surface. The selective catalytic reduction of NOx with NH3 tests indicate that MnOx-Fe2O3/TiO2/Ti monolithic catalysts exhibit excellent low-temperature catalytic performance with 100% of NOx conversion at 137 °C, good stability and water resistance, showing great potential and broad application prospects in comparison with powder catalysts and honeycomb ceramic catalysts. The strategy of depositing multi-components active catalysts on in-situ grown ultra-thin TiO2 nanosheet supports on flexible Ti mesh paves a solid way toward the practical applications of novel low-temperature selective catalytic reduction catalysts in diverse fields.