Fast microwave-assisted solvothermal synthesis of metal nanoparticles (Pd, Ni, Sn) supported on sulfonated MWCNTs: Pd-based bimetallic catalysts for ethanol oxidation in alkaline medium
Fast microwave-assisted solvothermal synthesis of metal nanoparticles (Pd, Ni, Sn) supported on sulfonated MWCNTs: Pd-based bimetallic catalysts for ethanol oxidation in alkaline medium
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DOI：
10.1016/j.electacta.2011.10.071
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发表时间：
2012
影响因子：
6.6
通讯作者：
T. Ramulifho;K. Ozoemena;R. M. Modibedi;C. Jafta;M. Mathe
中科院分区：
文献类型：
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作者：
T. Ramulifho;K. Ozoemena;R. M. Modibedi;C. Jafta;M. Mathe
采用快速微波辅助溶剂热法在磺化多壁碳纳米管(SF-MWCNTs)上制备了金属纳米颗粒(Pd、Ni、Sn)。研究了SF-MWCNT-Pd及其混合双金属电催化剂(SF-MWCNT-PdSnMixand SF-MWCNT-PdNimix)在碱性介质中对乙醇氧化的电催化行为。结果表明，单一的MWCNT-金属纳米复合材料经简单超声混合得到的混合Pd基催化剂比其合金纳米颗粒(金属盐共还原得到)或单独Pd具有更好的电催化活性。与未磺化和商品化的火神碳相比，SF-MWCNT平台具有更好的电催化性能。详细的电化学研究(包括循环伏安法、计时电流法、计时电位法和交流阻抗谱)证明了在SF-MWCNT-PdNimix平台上乙醇的电催化氧化比SF-MWCNT-PdSnimix平台更稳定，发生在更低的电位下，给出了更低的Tafel斜率，与SF-MWCNT-PdSnmi平台相比，具有更快的电荷转移动力学。此外，SF-MWCNT-PdNimix比SF-MWCNT-PdSnMix对CO中毒有更强的耐受性。这些结果为研究微波合成的Pd基双金属催化剂在直接乙醇碱性燃料电池技术中的潜在应用提供了一些重要的启示。
The preparation of metal nanoparticles (Pd, Ni, Sn) supported on sulfonated multi-walled carbon nanotubes (SF-MWCNTs) using a very rapid microwave-assisted solvothermal strategy has been described. Electrocatalytic behaviour of the SF-MWCNT-Pd and its ‘mixed’ bimetallic electrocatalysts (i.e., SF-MWCNT-PdSnmixand SF-MWCNT-PdNimix) towards ethanol oxidation in alkaline medium was investigated. The result shows that the mixed Pd-based catalysts (obtained by simple ultrasonic-mixing of the individual MWCNT-metal nanocomposites) gave better electrocatalytic activity than their alloy nanoparticles (obtained by co-reduction of metal salts) or Pd alone. The SF-MWCNT platform gave better electrocatalytic performance compared to the unsulfonated and commercial Vulcan carbons. Detailed electrochemical studies (involving cyclic voltammetry, chronoamperometry, chronopotentiometry, and impedance spectroscopy) prove that the electrocatalytic oxidation of ethanol at the SF-MWCNT-PdNimixplatform is more stable, occurs at lower potential, gives lower Tafel slopes, with faster charge-transfer kinetics compared to its SF-MWCNT-PdSnmixcounterpart. Also, result revealed that SF-MWCNT-PdNimixis more tolerant to CO poisoning than the SF-MWCNT-PdSnmix. The results provide some important insights into the electrochemical response of microwave-synthesised Pd-based bimetallic catalysts for potential application in direct ethanol alkaline fuel cell technology.