Pt-Ir binary hydrophobic catalysts: Effects of Ir content and particle size on catalytic performance for liquid phase catalytic exchange
Pt-Ir binary hydrophobic catalysts: Effects of Ir content and particle size on catalytic performance for liquid phase catalytic exchange
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DOI：
10.1016/j.ijhydene.2009.08.052
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发表时间：
2009-10
影响因子：
7.2
通讯作者：
Sheng Hu;Liang-ping Xiong;Xingbi Ren;Changbing Wang;Yangming Luo
中科院分区：
文献类型：
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作者：
Sheng Hu;Liang-ping Xiong;Xingbi Ren;Changbing Wang;Yangming Luo
在封闭的聚四氟乙烯容器中，采用微波辐射多元醇法合成了不同原子比的Pt/C和PtIr/C催化剂。表征结果表明，随着Ir含量的增加，铂-Ir的平均粒径变化不大，面心晶体结构逐渐变得无定形。通过改变合成溶液的pH值和微波加热速率可以控制颗粒的大小。然后将碳负载催化剂和聚四氟乙烯一起负载到泡沫镍(FN)载体上，得到疏水催化剂。给出了液相催化交换反应的反应机理，解释了疏水催化剂的催化活性最好的条件是铂/Ir摩尔比为4/1。此外，还考察了颗粒大小对催化性能的影响。Pt4Ir1/C/FN催化剂的平均粒径在2.5~3.8 nm范围内减小，活性得到提高。
Pt/C and Pt–Ir/C catalysts with different atomic ratios were synthesized in a closed PTFE vessel by a microwave-irradiated polyol method. The characterization results indicated that the average Pt–Ir particle size changed only slightly and the face-centered crystalline structure gradually became more amorphous with increasing iridium content. The particle size could be controlled by altering the pH of the synthesis solution and the microwave heating rate. The carbon-supported catalysts and polytetrafluoroethylene were then loaded together on a foamed nickel (FN) carrier to obtain hydrophobic catalysts. The reaction mechanisms were presented for liquid phase catalytic exchange reaction, which could explain that a hydrophobic catalyst with a Pt/Ir molar ratio of 4/1 exhibited the best catalytic activity. Furthermore, the effect of particle size on catalytic performance was investigated. The activity of the Pt4Ir1/C/FN catalyst was enhanced by decreasing the average particle size, in the range of 2.5–3.8nm.