Ternary Pt/Rh/SnO2 electrocatalysts for oxidizing ethanol to CO2
Ternary Pt/Rh/SnO2 electrocatalysts for oxidizing ethanol to CO2
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DOI：
10.1038/nmat2359
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发表时间：
2009-04-01
期刊：
影响因子：
41.2
通讯作者：
Adzic, R. R.
中科院分区：
文献类型：
--
作者：
Kowal, A.;Li, M.;Adzic, R. R.
乙醇具有高能量密度，可能由可再生资源生产，易于储存和运输，几乎是燃料电池的理想可燃物，其中其化学能可以直接转化为电能。然而，直接乙醇燃料电池的商业化受到乙醇缓慢、低效氧化的阻碍，即使在最好的电催化剂下也是如此（1，2）。我们合成了一个三元PtRhSnO 2/C电催化剂，通过沉积铂和铑原子上的碳载二氧化锡纳米粒子，能够氧化乙醇，具有高效率，并具有很大的希望，为解决发展实际的直接乙醇燃料电池的障碍。这种电催化剂在室温下在酸性溶液中有效地分裂乙醇中的C-C键，促进其在低电位下氧化成CO2，这是现有催化剂无法实现的。我们的实验和密度泛函理论计算表明，电催化剂的活性是由于其每个组成部分的具体性质，诱导它们的相互作用。这些发现有助于解释Pt-Ru对甲醇氧化的高活性和对乙醇氧化的缺乏活性，并指出在其他催化过程中实现C-C键裂解的方法。
Ethanol, with its high energy density, likely production from renewable sources and ease of storage and transportation, is almost the ideal combustible for fuel cells wherein its chemical energy can be converted directly into electrical energy. However, commercialization of direct ethanol fuel cells has been impeded by ethanol's slow, inefficient oxidation even at the best electrocatalysts(1,2). We synthesized a ternary PtRhSnO2/C electrocatalyst by depositing platinum and rhodium atoms on carbon-supported tin dioxide nanoparticles that is capable of oxidizing ethanol with high efficiency and holds great promise for resolving the impediments to developing practical direct ethanol fuel cells. This electrocatalyst effectively splits the C-C bond in ethanol at room temperature in acid solutions, facilitating its oxidation at low potentials to CO2, which has not been achieved with existing catalysts. Our experiments and density functional theory calculations indicate that the electrocatalyst's activity is due to the specific property of each of its constituents, induced by their interactions. These findings help explain the high activity of Pt-Ru for methanol oxidation and the lack of it for ethanol oxidation, and point to the way to accomplishing the C-C bond splitting in other catalytic processes.