Coupled s-p-d Exchange in Facet-Controlled Pd3Pb Tripods Enhances Oxygen Reduction Catalysis
Coupled s-p-d Exchange in Facet-Controlled Pd3Pb Tripods Enhances Oxygen Reduction Catalysis
复制标题
小面控制的 Pd3Pb 三脚架中的耦合 s-p-d 交换增强了氧还原催化
DOI：
10.1016/j.chempr.2018.01.002
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发表时间：
2018-02-08
期刊：
影响因子：
23.5
通讯作者：
Huang, Xiaoqing
中科院分区：
文献类型：
--
作者：
Bu, Lingzheng;Shao, Qi;Huang, Xiaoqing
高效的氧还原反应（ORR）催化剂是开发高性能燃料电池的关键。钯 (Pd) 是一种很有前景的 ORR 催化剂体系，因为它具有替代铂 (Pt) 的潜力；然而，它的活性通常低于 Pt。在这里，我们报告了一类主要具有 {110} 面的有序 Pd3Pb 三脚架 (TP)，并表明它们在碱性介质中实现了极高的 ORR 性能。与 Pt 催化剂优异的 ORR 活性是由其部分填充的 d 轨道引起的知识相反，我们的第一原理计算表明，Pd3Pb TPs {110} 面上的 Pd-4d 和 Pb-(sp) 轨道之间的强电荷交换导致 Pd-Pb 局部键合单元的轨道构型与 Pt 相似。因此，Pd3Pb TP 表现出比商业 Pt/C 和商业 Pd/C 高得多的 ORR 活性。 Pd3Pb TP 具有耐用性，可承受超过 20,000 次潜在循环，结构和成分变化可忽略不计。
Efficient oxygen reduction reaction (ORR) catalysts are key for the development of high-performance fuel cells. Palladium (Pd) is a promising catalyst system for ORR given its potential to replace platinum (Pt); however, it usually exhibits lower activity than Pt. Here, we report a class of ordered Pd3Pb tripods (TPs) with predominantly {110} facets and show that they achieve extremely high ORR performance in alkaline medium. In contrast to the knowledge that the excellent ORR activity of Pt catalyst is caused by its partially filled d orbital, our first-principle calculations suggest that the strong charge exchange between Pd-4d and Pb-(sp) orbitals on the Pd3Pb TPs {110} facet results in a Pd-Pb local bonding unit with an orbital configuration similar to that of Pt. Consequently, Pd3Pb TPs exhibit much higher ORR activities than commercial Pt/C and commercial Pd/C. Pd3Pb TPs are endurable and sustain over 20,000 potential cycles with negligible structural and compositional changes.