Ternary Electrocatalysts for Oxidizing Ethanol to Carbon Dioxide: Making Ir Capable of Splitting C-C Bond
Ternary Electrocatalysts for Oxidizing Ethanol to Carbon Dioxide: Making Ir Capable of Splitting C-C Bond
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DOI：
10.1021/ja306384x
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发表时间：
2013-01-09
影响因子：
15
通讯作者：
Adzic, Radoslav R.
中科院分区：
文献类型：
--
作者：
Li, Meng;Cullen, David A.;Adzic, Radoslav R.
C-C 键断裂是乙醇电氧化 (EOR) 生成 CO2 的主要障碍。我们最近证明，三元 PtRhSnO2 电催化剂可以在室温下完成该反应，而 Rh 具有独特的 C-C 键分裂能力。在本文中，我们报告了作为三元催化剂的组分，Ir 可以被诱导裂解 C-C 键的发现。我们表征并比较了几种碳负载纳米粒子 (NP) 电催化剂的性能，这些催化剂包含使用种子生长方法制备的多金属纳米岛（MM' = PtIr、PtRh、IrRh、PtIrRh）装饰的 SnO2 NP 核。采用一系列表征技术来确定合成的 MM'/SnO2 NP 的组成和结构，同时电化学和原位红外反射吸收光谱研究阐明了活性趋势以及反应中间体和产物的性质。与传统的 Pt/C 和 Pt/SnO2/C 催化剂相比，这些 MM'/SnO2/C 电催化剂的 EOR 反应活性和 CO2 形成选择性均显着更高。我们证明，高 Ir 含量的 PtIr/SnO2/C 催化剂表现出出色的催化性能，具有最负的 EOR 起始电位以及对乙醇完全氧化为 CO2 的相当好的选择性。
Splitting the C-C bond is the main obstacle to electrooxidation of ethanol (EOR) to CO2. We recently demonstrated that the ternary PtRhSnO2 electrocatalyst can accomplish that reaction at room temperature with Rh having a unique capability to split the C-C bond. In this article, we report the finding that Ir can be induced to split the C-C bond as a component of the ternary catalyst. We characterized and compared the properties of several carbon-supported nanoparticle (NP) electrocatalysts comprising a SnO2 NP core decorated with multimetallic nanoislands (MM' = PtIr, PtRh, IrRh, PtIrRh) prepared using a seeded growth approach. An array of characterization techniques were employed to establish the composition and architecture of the synthesized MM'/SnO2 NPs, while electrochemical and in situ infrared reflection absorption spectroscopy studies elucidated trends in activity and the nature of the reaction intermediates and products. Both EOR reactivity and selectivity toward CO2 formation of several of these MM'/SnO2/C electrocatalysts are significantly higher compared to conventional Pt/C and Pt/SnO2/C catalysts. We demonstrate that the PtIr/SnO2/C catalyst with high Ir content shows outstanding catalytic properties with the most negative EOR onset potential and reasonably good selectivity toward ethanol complete oxidation to CO2.