Study on Methanol Oxidation at Pt and PtRu Electrodes by Combining in situ Infrared Spectroscopy and Differential Electrochemical Mass Spectrometry
Study on Methanol Oxidation at Pt and PtRu Electrodes by Combining in situ Infrared Spectroscopy and Differential Electrochemical Mass Spectrometry
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DOI：
10.1063/1674-0068/27/05/541-547
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发表时间：
2014-11
影响因子：
1
通讯作者：
Q. Tao;Wei Chen;Yao Yao-Yao;A. Yousaf;Yanxia Chen
中科院分区：
文献类型：
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作者：
Q. Tao;Wei Chen;Yao Yao-Yao;A. Yousaf;Yanxia Chen
在恒电位条件下，用衰减全反射结构的原位FTIR光谱和微分电化学质谱法研究了在0.1 mol/L HClO4+0.5 mol/L MeOH中沉积不同量Ru（记为Pt x Ru y，标称覆盖率y分别为0.17、0.27和0.44 ML）的Pt和Pt电极表面上的甲醇氧化反应（MOR）。结果表明：(1)在0.3 V ~ 0.6 V（相对于RHE）电位范围内，在Pt和PtRu电极上，CO是唯一的甲醇相关吸附物；（ii）在pt0.56 - ru0.44处，检测到两条红外波段，一条来自Ru岛吸附的CO，另一条来自Pt基底上的COL，而在其他电极处，只有一条来自Pt吸附的COL；（iii） MOR活性从Pt0.73Ru0.27 >Pt0.56Ru0.44 > Pt0.83Ru0.17 >Pt依次降低；（iv）在0.5 V时，Pt0.73Ru0.27的MOR产生CO2的电流效率达到50%，CH3OH转化为CO2的频率约为0.1分子/（位·秒）。提出了进一步改进PtRu MOR催化剂的建议。
Methanol oxidation reaction (MOR) at Pt and Pt electrode surface deposited with various amounts of Ru (denoted as Pt x Ru y , nominal coverage y is 0.17, 0.27, and 0.44 ML) in 0.1 mol/L HClO4+0.5 mol/L MeOH has been studied under potentiostatic conditions by in situ FTIR spectroscopy in attenuated-total-reflection configuration and differential electrochemical mass spectrometry under controlled flow conditions. Results reveal that (i) CO is the only methanol-related adsorbate observed by IR spectroscopy at all the Pt and PtRu electrodes examined at potentials from 0.3 V to 0.6 V (vs. RHE); (ii) at Pt0.56Ru0.44, two IR bands, one from CO adsorbed at Ru islands and the other from COL at Pt substrate are detected, while at other electrodes, only a single band for COL adsorbed at Pt is observed; (iii) MOR activity decreases in the order of Pt0.73Ru0.27 >Pt0.56Ru0.44 > Pt0.83Ru0.17 > Pt; (iv) at 0.5 V, MOR at Pt0.73Ru0.27 reaches a current efficiency of 50% for CO2 production, the turn-over frequency from CH3OH to CO2 is ca. 0.1 molecule/(site·sec). Suggestions for further improving of PtRu catalysts for MOR are provided.