Promotional effect of surface treated N-TiO2 as support for VOx-based catalysts on the selective catalytic reduction of NO using NH3

Highlights: • Nitrogen doped TiO₂ (N-TiO₂) support added catalyst is developed for selective catalytic reduction of NO_x. • N-TiO₂ has abundant surface functional groups and meso-porous structure which could disperse the active materials. • N-TiO₂ added catalyst provides high NO_x conversion efficiency of >90% over a wide temperature range (250 to 400 °C) Selective catalytic reduction (SCR) catalysts, which are widely used to mitigate rising nitrogen oxide (NOx) pollution originating from fine dust, are associated with issues such as a limited operating temperature range and the demand for a higher NOx conversion efficiency. Specifically, to increase NOx conversion efficiency, increasing catalytic reaction sites by improving specific surface area (SSA) and dispersing catalytic active particles across the catalyst are of great significance. When active materials have low dispersibility, their activity is lowered owing to aggregation and crystallisation as the catalytic material content increases. To address this issue, it is necessary to realize the dispersion of active materials, while ensuring that no aggregation via the surface occurs. In this study, we investigated the use of N-doped TiO₂ (N-TiO₂) to disperse the active particles. Approximately 17 at.% N-doped was into the TiO₂ support. The results obtained showed that the addition of these supports resulted in the even dispersion of the active materials on the catalyst surface, yielding abundant anchoring sites, which improved SSA, as confirmed by the transmission electron microscopy analysis of the textural properties of the catalysts. Further, these catalysts exhibited high catalytic activity over a wide temperature range (200–400 °C).