Identification of Surface Reactivity Descriptor for Transition Metal Oxides in Oxygen Evolution Reaction.
Identification of Surface Reactivity Descriptor for Transition Metal Oxides in Oxygen Evolution Reaction.
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DOI：
10.1021/jacs.6b05398
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发表时间：
2016-08
影响因子：
15
通讯作者：
H. Tao;Liwen Fang;Jiazang Chen;H. Yang;Jiajian Gao;J. Miao;Shengli Chen;B. Liu
中科院分区：
文献类型：
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作者：
H. Tao;Liwen Fang;Jiazang Chen;H. Yang;Jiajian Gao;J. Miao;Shengli Chen;B. Liu
许多重要的反应，如析氧反应(OER)，都是由过渡金属氧化物(TMOS)催化的，其表面反应活性相当难以捉摸。因此，合理调整中间体在TMOS上的吸附能以获得理想的催化性能仍然是一个巨大的挑战。在这里，我们展示了一个普遍的和可调的表面结构，配位不饱和金属阳离子(MCU)，作为OER中TMOS的良好表面反应性描述。TMO的表面反应性随着MCU密度的增加而单调增加，因此MCU的增加提高了弱结合TMO的催化活性，但削弱了强结合TMO的催化活性。本文提出的一个新的模型可以很好地解释表面反应性的电子来源，其中最高占据d态相对于费米能级的能量通过影响反键态的填充来决定中间体的成键强度。我们的模型首次很好地描述了TMO之间的反应性趋势，并将启动可行的OER催化剂设计原则，但不限于此。
A number of important reactions such as the oxygen evolution reaction (OER) are catalyzed by transition metal oxides (TMOs), the surface reactivity of which is rather elusive. Therefore, rationally tailoring adsorption energy of intermediates on TMOs to achieve desirable catalytic performance still remains a great challenge. Here we show the identification of a general and tunable surface structure, coordinatively unsaturated metal cation (MCUS), as a good surface reactivity descriptor for TMOs in OER. Surface reactivity of a given TMO increases monotonically with the density of MCUS, and thus the increase in MCUS improves the catalytic activity for weak-binding TMOs but impairs that for strong-binding ones. The electronic origin of the surface reactivity can be well explained by a new model proposed in this work, wherein the energy of the highest-occupied d-states relative to the Fermi level determines the intermediates' bonding strength by affecting the filling of the antibonding states. Our model for the first time well describes the reactivity trends among TMOs, and would initiate viable design principles for, but not limited to, OER catalysts.