Polyol-Mediated Synthesis of V 2 O 5 -WO 3 /TiO 2 Catalysts for Low-Temperature Selective Catalytic Reduction with Ammonia.

We demonstrated highly efficient selective catalytic reduction catalysts by adopting the polyol process, and the prepared catalysts exhibited a high nitrogen oxide (NO X ) removal efficiency of 96% at 250 °C. The V 2 O 5 and WO 3 catalyst nanoparticles prepared using the polyol process were smaller (~10 nm) than those prepared using the impregnation method (~20 nm), and the small catalyst size enabled an increase in surface area and catalytic acid sites. The NO X removal efficiencies at temperatures between 200 and 250 °C were enhanced by approximately 30% compared to those of the catalysts prepared using the conventional impregnation method. The NH 3 -temperature-programmed desorption and H 2 -temperature-programmed reduction results confirmed that the polyol process produced more surface acid sites at low temperatures and enhanced the redox ability. The in situ Fourier-transform infrared spectra further elucidated the fast absorption of NH 3 and its reduction with NO and O 2 on the prepared catalyst surfaces. This study provides an effective approach to synthesizing efficient low-temperature SCR catalysts and may contribute to further studies related to other catalytic systems.