关键词: 催化剂, 催化剂载体, 粒度, NO _x 转化率, 抗水硫中毒

Abstract:

The RuO _x -doped VWTi catalyst (RVWTi), supported by TiO₂, has emerged as a promising industrial low-temperature denitration catalyst due to its excellent low-temperature denitration activity and resistance to water and sulfur poisoning. However, the particle size of the TiO₂ support significantly impacts the catalytic performance, leading to challenges in ensuring performance stability. In this study, RVWTi catalysts were prepared using TiO₂ supports with particle sizes of 5nm, 20nm, 30nm, and 50nm. Their denitration activity, physicochemical properties, and resistance to water and sulfur poisoning were systematically evaluated. Under conditions of [NO]=[NH₃]=550μL/L, [O₂]=16%, GHSV=28000h⁻¹, and a reaction temperature of 150℃, the catalyst supported on 30nm TiO₂ exhibited the best denitration performance, achieving an NO _x conversion rate of 85.7%. This superior performance was attributed to its higher surface chemisorbed oxygen content and greater proportion of V⁴⁺ species. The catalyst supported on 5nm TiO₂ exhibited the worst performance, with an NO _{xconversion rate of only 56.9%, due to the high degree of agglomeration and reduced specific surface area. The resistance to water and sulfur poisoning tests showed that the catalyst prepared with 30nm TiO2 support exhibited the best performance under conditions of 10% water vapor and 35mg/m³ SO2. This was primarily attributed to its larger specific surface area, higher surface NH₃ adsorption capacity, and inhibitory effect on the formation of ammonium sulfate salts. This study elucidates the influence of TiO2 support particle size on the performance of the catalyst, revealing its effects on catalytic activity and anti-poisoning mechanisms. Furthermore, it provides technical support for optimizing catalyst formulations.}

Key words: catalyst, catalyst support, granularity, NO _x conversion rate, water/sulfur poisoning resistance