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

摘要：

以TiO₂为载体的RuO _x 掺杂VWTi催化剂（RVWTi）因其优异的低温脱硝活性和抗水硫中毒性能，已成为工业烟气低温脱硝催化剂开发的重要方向。然而，TiO₂载体的粒度对催化剂性能有显著影响，导致其性能稳定性存在不足。本文以5nm、20nm、30nm和50nm四种粒度的TiO₂为载体制备RVWTi催化剂，系统评价其脱硝活性、物化性能及抗水硫中毒性能。在[NO]=[NH₃]=550μL/L、[O₂]=16%、GHSV=28000h⁻¹及150℃的条件下，30nm TiO₂载体催化剂表现出最优脱硝性能，NO _x 转化率达85.7%，优异性能归因于其较高的表面化学吸附氧含量和V⁴⁺物种比例。5nm TiO₂载体催化剂因团聚程度较高、比表面积较小，表现最差，NO _x 转化率仅为56.9%。抗水硫中毒性能测试表明，30nm TiO₂载体制备的催化剂在含10%（体积分数）水蒸气和35mg/m³ SO₂条件下表现最佳，主要得益于其最大比表面积、较高的表面吸附NH₃能力及对硫酸铵盐生成的抑制作用。本文阐明了载体粒度TiO₂对催化剂性能的影响规律，揭示了其对催化剂活性及抗中毒机理的影响，并为催化剂配方优化提供了技术支撑。

关键词: 催化剂, 催化剂载体, 粒度, NO _x 转化率, 抗水硫中毒