• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>RSC Advances >New insights into the deactivation mechanism of V2O5-WO3/TiO2 catalyst during selective catalytic reduction of NO with NH3: synergies between arsenic and potassium species
【24h】

New insights into the deactivation mechanism of V2O5-WO3/TiO2 catalyst during selective catalytic reduction of NO with NH3: synergies between arsenic and potassium species

机译：NH3选择性催化还原NO时V2O5-WO3 / TiO2催化剂失活机理的新见解：砷和钾物种之间的协同作用

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Synergies between arsenic (As) and potassium (K) species in the deactivation of V _(2) O _(5) -WO _(3) /TiO _(2) catalyst were investigated. Both arsenic oxide and potassium species presented a serious poisoning impact on catalyst activities, and the extent of poisoning of (As + K) was much stronger than their single superposition. The intrinsic reasons were explored and analyzed by N _(2) physisorption, XPS, H _(2) -TPR, NH _(3) -TPD, NH _(3) -DRIFTS and in situ FTIR. Results indicated that BET surface area decreased due to the formation of a dense arsenic coating on the catalyst surface. V–OH active sites were destroyed by arsenic and As–OH acid sites were newly generated. After potassium species were added to arsenic-poisoned catalyst, K ~(+) further neutralized the As–OH acid sites, and the amount and stability of both Lewis and Br?nsted acid sites decreased more greatly. Potassium also reacted with intermediate NH _(2) ~(?) when the temperature was elevated to higher than 250 °C, which resulted in more NH _(3) consumption and NH _(3) -SCR reaction inhibition. The extent of deactivation was related to the potassium species when both poisons reacted on the catalyst, and the influence sequence followed AsKS < AsKN < AsKC. As _(2) O _(3) + K _(2) SO _(4) presented the weakest impact among these three poisoned catalysts due to the resistance of SO _(4) ~(2?) to arsenic.
机译：研究了V_（2）O_（5）-WO_（3）/ TiO_（2）催化剂失活过程中砷（As）和钾（K）之间的协同作用。氧化砷和钾都对催化剂的活性产生了严重的中毒影响，（As + K）的中毒程度比它们的单一叠加作用强得多。通过N _（2）物理吸附，XPS，H _（2）-TPR，NH _（3）-TPD，NH _（3）-DRIFTS和原位FTIR探索和分析了内在原因。结果表明，由于在催化剂表面上形成致密的砷涂层，BET表面积减小。 V-OH活性位点被砷破坏，而As-OH酸性位点又重新产生。向砷中毒的催化剂中加入钾离子后，K〜（+）进一步中和了As-OH的酸性位，路易斯和布朗斯台德酸性位的数量和稳定性均大大降低。当温度升高到高于250°C时，钾也与中间体NH _（2）〜（？）反应，导致更多的NH _（3）消耗和NH _（3）-SCR反应抑制。当两种毒物在催化剂上反应时，失活的程度与钾的种类有关，其影响顺序遵循AsKS

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号