CuPt and CuPtRu Nanostructures for Ammonia Oxidation Reaction
CuPt and CuPtRu Nanostructures for Ammonia Oxidation Reaction
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DOI：
10.1149/08512.0177ecst
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发表时间：
2018-03
期刊：
影响因子：
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通讯作者：
R. Manso;Lianghao Song;Zhixiu Liang;Jia X. Wang;Jingyi Chen
中科院分区：
文献类型：
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作者：
R. Manso;Lianghao Song;Zhixiu Liang;Jia X. Wang;Jingyi Chen
甲醇、乙醇和氨等液体燃料由于其存储和分配成本较低，是燃料电池中氢的有吸引力的替代品。缺乏足够活性的催化剂来进行氧化反应是一个障碍。我们之前的研究发现，对于酸性中的甲醇氧化反应（MOR），Pt3Cu 纳米枝晶比 Pt 纳米粒子具有更高的活性和耐久性。在这项研究中，我们通过种子介导的 Pt 和 Ru 在 Cu 上的生长合成了两种类型的 CuPt 和 CuPtRu 催化剂纳米结构，并测试了它们在碱性溶液中氨氧化反应 (AOR) 的性能。与 MOR 不同，纳米枝晶不会促进 AOR 活性 - CuPt 的性能与 Pt 相似，而 CuPtRu 的活性低于 Pt。有趣的是，与 Pt 纳米颗粒相比，CuPt 纳米线上的 AOR 峰值电流增加了 64%，CuPtRu 纳米线上的 AOR 峰值电流增加了 330%。这些结果表明，AOR 更喜欢长纳米线上的扩展表面，这与 MOR 明显不同。这可能是由两个因素造成的：NH3 氧化成 N2 涉及两个含 N 中间体的二聚化以形成 N-N 键，并且吸附中间体的扩散面一般在平台上低于在低配位位点上。这表明表面形态的强大影响将被进一步研究并用于开发先进的 AOR 纳米催化剂。
Liquid fuels, such as methanol, ethanol, and ammonia, are attractive alternative to hydrogen for fuel cells due to their lower costs for storage and distribution. Lack of sufficiently active catalysts for their oxidation reactions is a roadblock. Our previous study found that Pt3Cu nanodendrites yielded higher activity and durability than Pt nanoparticles for methanol oxidation reaction (MOR) in acid. In this study, we synthesized two types of nanostructures of CuPt and CuPtRu catalysts via seed-mediated growth of Pt and Ru on Cu and tested their performance for ammonia oxidation reaction (AOR) in alkaline solution. Unlike for MOR, the nanodendrites do not promote AOR activity - CuPt performs similar to Pt and CuPtRu is less active than Pt. Interestingly, the AOR peak current is increased by 64% on CuPt nanowires and 330% on CuPtRu nanowires as compared to Pt nanoparticles. These results suggest that AOR prefers extended surface on long nanowires, distinctly differing from MOR. This can be contributed to two factors: NH3 oxidization to N2 involves dimerization of two N-containing intermediates to form the N-N bond and diffusion batters for adsorbed intermediates are generally lower on terrace than at low-coordination sites. This demonstrated strong effect of surface morphology will be further studied and utilized in developing advanced AOR nanocatalysts.