【摘要】 以多壁碳纳米管(MWCNTs)为载体,制备了Pt载量为20%的Pt-(RuOxHy)m/MWCNTs催化剂(m为Ru/Pt原子比),在m≤0.4时考察了不同电势区间循环伏安预处理对其催化性能的影响.水合氧化钌(RuOxHy)的存在明显提高了Pt催化剂抗CO毒化的能力,而在甲醇电氧化反应中Pt的质量比活性(MSA)随样品中m值增大呈先升后降趋势.经低电势区间(-0.20-0.46 V vs SCE)预处理稳定的催化剂中,Pt-(RuOxHy)0.10/MWCNTs样品中Pt的甲醇电氧化反应的MSA提高至相应单组分Pt/MWCNTs的9倍.将预处理电势区间扩展到高电势(即-0.20-0.96 v vs SCE)会造成钌组分溶解流失,导致催化剂抗CO毒化能力下降.在经过高电势区间的预处理后,Pt-(RuOxHy)020/MWCNTs对甲醇电氧化反应呈现出最高的催化活性,为单组分Pt催化剂的1.4倍.这些结果证实,水合氧化钉是Pt电催化剂的有效助剂.更多还原

【Abstract】 A series of Pt-(RuOxHy)m/MWCNTs catalysts(m being the Ru/Pt atomic ratio) containing 20% Pt were prepared using multi-walled carbon nanotubes(MWCNTs) as the support.The activity towards CO and methanol electro-oxidation of Pt in these catalysts after repeated cyclic voltammetry treatments in low(-0.20-0.46 V vs SCE) and extended(-0.20-0.96 V vs SCE) potential regions was investigated.The results showed that the presence of hydrous ruthenium oxide(RuOxHy) significantly reduced the over-potential of CO electro-oxidation on Pt,and the activity of Pt in Pt-(RuOxHy)m/MWCNTs for methanol electro-oxidation could thus be maximized by proper tuning of m.After the treatment in the low potential region,the mass-specific activity(MSA) of Pt in Pt-(RuOxHy)m/MWCNTs of m = 0.10 for methanol electro-oxidation increased by nearly 9 times that in Pt/MWCNTs.Significant dissolution of RuOxHy species was detected after the pretreatment in the extended potential region,which resulted in reduced CO tolerance and changed the activity order of Pt-(RuOxHy)m/MWCNTs catalysts for methanol electro-oxidation.In this case,Pt in the sample with m = 0.20 showed the highest MSA,which was still 40% higher than that of Pt/MWCNTs.更多还原