• 关键词：蜂窝状Pt/Al₂O₃  NO_x转化率  焙烧温度  焙烧时间  空速

• 基金项目：

• 李哲
• 太原理工大学煤科学与技术教育部和山西省重点实验室, 化学工程与技术学院, 太原 030024

• 黄伟
• 太原理工大学煤科学与技术教育部和山西省重点实验室, 化学工程与技术学院, 太原 030024

• 任军
• 太原理工大学煤科学与技术教育部和山西省重点实验室, 化学工程与技术学院, 太原 030024

• 谢克昌
• 太原理工大学煤科学与技术教育部和山西省重点实验室, 化学工程与技术学院, 太原 030024

• 摘要：采用多次涂层浸渍法制备了蜂窝状Pt/Al₂O₃催化剂.并对焙烧温度和焙烧时间等不同制备条件和反应温度、O₂浓度和空速等不同反应条件下NO_{x的选择性催化还原性能进行了研究.实验表明, 蜂窝状PtAl2O3催化剂上NOx转化率在反应温度为30.0℃左右时出现最高值.而随反应温度的升高, 达到最高转化率所需的O2浓度不断减小, 分别为8%, 6%和4%.这可能是由于在高温下O2会与NO发生竞争吸附, 从而阻碍了NO催化还原反应的进行;同时随着空速的依次增加, 催化剂的活性逐渐下降, 催化剂活性曲线的峰值依次向高温方向移动.实验还说明, 在过高的焙烧温度和较长的焙烧时间的制备条件下, 蜂窝状Pt/Al2O3的催化性能明显下降.这是因为高的焙烧温度和较长的焙烧时间能够导致蜂窝状Pt/Al2O3催化剂的表面发生烧结现象, 使得催化剂的比表面减小, 从而导致活性降低.}

• Abstract：A honeycomb Pt/Al₂O₃ catalyst was prepared by mult-coating and wet impregnation method. The performance for NO_x selective catalytic reduction under the conditions of different calcinations time, calcinations temperature, O₂ concentration and space velocity was studied. The results showed that the honeycomb Pt/Al₂O₃ exhibited the highest value for NO_x conversion at about 300℃. With rising of temperature, the O₂ concentration decreases when NO_x conversion reaches the top value. With rising of O₂ concentration, the catalytic activity declined at higher temperature. It may be attributed that the decomposition of NO_x on the catalyst surface was inhibited by superfluous O₂ at higher temperature. The results also indicated that catalytic activity of honeycomb Pt/Al₂O₃ declined at higher calcinations temperature and longer calcinations time, because the catalyst can be sintered under this condition and results in reduction of its surface area.

• Key words：honeycomb Pt/Al₂O₃  NO_x conversion  calcinations temperature  calcinations time  space velocity

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