2D Covalent Metals: A New Materials Domain of Electrochemical CO2 Conversion with Broken Scaling Relationship.
2D Covalent Metals: A New Materials Domain of Electrochemical CO2 Conversion with Broken Scaling Relationship.
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DOI：
10.1021/acs.jpclett.6b01876
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发表时间：
2016-10
期刊：
影响因子：
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通讯作者：
Hyeyoung Shin;Yoonhoo Ha;Hyungjun Kim
中科院分区：
文献类型：
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作者：
Hyeyoung Shin;Yoonhoo Ha;Hyungjun Kim
为了实现可持续的碳循环，电化学将二氧化碳转化为有价值的燃料引起了人们的广泛关注。然而，由于中间体和产物的吸附能之间存在很强的相关性，导致反应动力学迟缓和过电位过高，这是电化学CO2转化的主要障碍。本文表明，具有零带隙的二维共价金属可以克服传统金属和金属合金的固有限制，从而由于其共价特性而大大降低了CO2还原的过电位。从基于第一性原理的61种2D共价金属的高通量筛选结果中，我们发现COOH和CO吸附能之间的强相关性可以完全被打破。这导致了除析氢反应催化剂外，CO2-to-CO和CO2-to-CH4转化催化剂的计算设计。为了实现高效的二氧化碳还原电化学催化剂，这项工作提出了一个新的材料领域，在单一材料中具有两种相互矛盾的性质：共价性和导电性。
Toward a sustainable carbon cycle, electrochemical conversion of CO2 into valuable fuels has drawn much attention. However, sluggish kinetics and a substantial overpotential, originating from the strong correlation between the adsorption energies of intermediates and products, are key obstacles of electrochemical CO2 conversion. Here we show that 2D covalent metals with a zero band gap can overcome the intrinsic limitation of conventional metals and metal alloys and thereby substantially decrease the overpotential for CO2 reduction because of their covalent characteristics. From first-principles-based high-throughput screening results on 61 2D covalent metals, we find that the strong correlation between the adsorption energies of COOH and CO can be entirely broken. This leads to the computational design of CO2-to-CO and CO2-to-CH4 conversion catalysts in addition to hydrogen-evolution-reaction catalysts. Toward efficient electrochemical catalysts for CO2 reduction, this work suggests a new materials domain having two contradictory properties in a single material: covalent nature and electrical conductance.