School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR, 97331, USA.
Adv Mater. 2017 Jun;29(23). doi: 10.1002/adma.201606800. Epub 2017 Apr 10.
Exploring efficient and low-cost electrocatalysts for the oxygen-reduction reaction (ORR) and oxygen-evolution reaction (OER) is critical for developing renewable energy technologies such as fuel cells, metal-air batteries, and water electrolyzers. A rational design of a catalyst can be guided by identifying descriptors that determine its activity. Here, a descriptor study on the ORR/OER of spinel oxides is presented. With a series of MnCo O , the Mn in octahedral sites is identified as an active site. This finding is then applied to successfully explain the ORR/OER activities of other transition-metal spinels, including Mn Co O (x = 2, 2.5, 3), Li Mn O (x = 0.7, 1), XCo O (X = Co, Ni, Zn), and XFe O (X = Mn, Co, Ni). A general principle is concluded that the e occupancy of the active cation in the octahedral site is the activity descriptor for the ORR/OER of spinels, consolidating the role of electron orbital filling in metal oxide catalysis.
探索高效且低成本的电催化剂对于开发可再生能源技术（如燃料电池、金属-空气电池和水电解槽）至关重要。通过确定决定其活性的描述符，可以对催化剂进行合理的设计。本文对尖晶石氧化物的氧还原反应（ORR）和氧析出反应（OER）进行了描述符研究。通过一系列 MnCoO ，确定了八面体位置的 Mn 为活性位。这一发现随后被成功应用于解释其他过渡金属尖晶石的 ORR/OER 活性，包括 MnCoO（x=2、2.5、3）、LiMnO（x=0.7、1）、XCoO（X=Co、Ni、Zn）和 XFeO（X=Mn、Co、Ni）。得出了一个普遍的原则，即八面体位置活性阳离子的 e 占据数是尖晶石 ORR/OER 的活性描述符，这巩固了电子轨道填充在金属氧化物催化中的作用。
