摘要
以异丙醇为分散溶剂与还原剂,采用高压微波加热法制备了Pt/C催化剂,研究了不同实验条件对Pt尺寸的影响,利用XRD、TEM对催化剂进行了表征。再将Pt/C催化剂和聚四氟乙烯混合,负载至泡沫镍上得到疏水催化剂,研究其对氢-水液相催化交换反应的催化性能。结果表明:加入保护剂乙酸钠、羟基乙酸钠、柠檬酸氢二钠后,Pt/C催化剂的活性金属团聚现象减少,Pt平均尺寸明显减小(由4.4nm分别降低到2.3、2.5、2.3nm);升温速率对Pt尺寸影响较大,随着升温速率的提高,活性金属Pt的尺寸减小;而pH的变化对Pt粒子的尺寸影响较小。加入保护剂有利于氢-水交换反应的催化剂活性,Pt尺寸为2.3～4.4nm时,催化剂活性随Pt尺寸减小而提高。
Pt/C catalysts with isopropanol as both dispersant and reducing agent were synthesized by microwave-irradiated polyol method.The microstructures of the catalysts were characterized by XRD and TEM.The effects of capping agents,pH and heating rate on Pt particle size were studied.Then Pt/C catalysts were loaded on foam nickel with polytetrafluoroethylene latex to obtain hydrophobic catalysts,and their catalytic activities for hydrogen-water liquid phase exchange reaction were investigated.The results show that compared to the non-capped Pt/C catalysts,the average size of Pt particles in sodium acetate,sodium glycollate and disodium hydrogen citrate capped Pt/C catalysts decreases from 4.4 nm to 2.3,2.5,and 2.3 nm respectively,and the agglomeration of Pt particles becomes obscure.The mean size of Pt particles in Pt/C catalysts decreases evidently with the increasing of the heating rate.However,the mean sizes of Pt particles in the Pt/C catalysts prepared with different pH of the synthesis solution are similar.The activity of the hydrophobic catalysts with capping agents is high for hydrogen-water liquid exchange reaction,and is enhanced by decreasing the average particle size,in the range of 2.3-4.4 nm.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2012年第7期780-785,共6页
Atomic Energy Science and Technology
基金
国家自然科学基金资助项目(20901071)
国家磁约束聚变能研究专项资助(2011GB11102)
