Engineering nanostructures of PGM-free oxygen-reduction catalysts using metal-organic frameworks
Engineering nanostructures of PGM-free oxygen-reduction catalysts using metal-organic frameworks
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DOI：
10.1016/j.nanoen.2016.11.033
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发表时间：
2017
期刊：
影响因子：
17.6
通讯作者：
Hanguang Zhang;H. Osgood;Xiaohong Xie;Yuyan Shao;Gang Wu
中科院分区：
文献类型：
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作者：
Hanguang Zhang;H. Osgood;Xiaohong Xie;Yuyan Shao;Gang Wu
氧还原反应（ORR）是燃料电池、金属空气电池等能量转换和储存装置的重要电化学反应之一。然而，需要大量的Pt来催化空气阴极处的动力学缓慢的ORR，因此极大地限制了它们的大规模实施。开发高性能的不含铂族金属（PGM）的ORR催化剂一直是这些清洁能源技术的长期目标。然而，目前的不含PGM的催化剂仍然显著地遭受不足的活性和有限的耐久性，特别是在更具挑战性的酸性介质中，例如质子交换膜（PEM）燃料电池。近年来，由金属离子和配体构成的金属有机骨架（MOFs）作为一种新型的无铂族金属催化剂的前驱体，在催化剂的合成中取得了令人鼓舞的进展。与其他催化剂前体相比，M0 F具有明确的晶体结构，具有容易调节的化学性质，并且含有所有所需的元素（例如，碳、氮和金属）。在这里，我们提供了一个帐户最近的创新铂族金属催化剂的设计和合成来自独特的MOF前体，特别强调工程纳米结构和催化剂的形态。我们的目标是为设计和合成先进的无铂族金属催化剂提供新的见解，这些催化剂具有增加的活性位点密度和3D框架网络中的受控键合。此外，我们还讨论了使用定义明确的MOF前体建立模型系统来阐明结构-性质相关性和活性中心性质的可能性。
Oxygen reduction reaction (ORR) is one of the essential electrochemical reactions for the energy conversion and storage devices such as fuel cells and metal-air batteries. However, a large amount of Pt is required for catalyzing the kinetically sluggish ORR at the air cathode, therefore greatly limiting their large scale implementation. Development of high-performance platinum group-metal (PGM)-free ORR catalysts has been a long-term goal for these clean energy technologies. However, current PGM-free catalysts are still significantly suffering from insufficient activity and limited durability especially in more challenging acidic media, such as proton exchange membrane (PEM) fuel cells. Recently, metal-organic frameworks (MOFs), constructed from bridging metal ions and ligands, have emerged as a new type of attractive precursors for the synthesis of PGM-free catalysts, which has led to encouraging performance improvement. Compared to other catalyst precursors, MOFs have well-defined crystal structure with readily tunable chemistry and contain all required elements (e.g., carbon, nitrogen, and metal). Here, we provide an account of recent innovative PGM-free catalyst design and synthesis derived from the unique MOF precursors with special emphasis on engineering nanostructure and morphology of catalysts. We aim to provide new insights into the design and synthesis of advanced PGM-free catalysts with increased density of active sites and controlled bonding in 3D frame network. In addition, we also discuss the possibility to use the well-defined MOF precursors for building up model systems to elucidate the structure-property correlations and the nature of active sites.