Computational Discovery of Active and Selective Metal‐Nitrogen‐Graphene Catalysts for Electrooxidation of Water to H 2 O 2
Computational Discovery of Active and Selective Metal‐Nitrogen‐Graphene Catalysts for Electrooxidation of Water to H 2 O 2
复制标题
计算发现用于水电氧化成 H 2 O 2 的活性和选择性金属-氮-石墨烯催化剂
DOI：
10.1002/cctc.202300055
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发表时间：
2023
期刊：
影响因子：
4.5
通讯作者：
Alexandrov, Vitaly
中科院分区：
文献类型：
--
作者：
Chaudhary, Payal;Evazzade, Iman;Belosludov, Rodion;Alexandrov, Vitaly
从 O2 或 H2O 直接电合成 H2O2 是替代能源密集型工业蒽醌工艺的一种有吸引力的策略。与氧还原反应相比，双电子水氧化反应（2e-WOR）具有多种优点，例如由于不存在气相反应物而具有更好的传质效果。然而，2e-WOR 是一个更具挑战性且研究较少的过程，只有少数金属氧化物表现出合理的活性/选择性特性。在这里，我们采用密度泛函理论计算来筛选各种用于 2e-WOR 的金属-氮-石墨烯结构。由于反应中间体的吸附能之间存在比例关系，我们确定了 2e-WOR 的第一和第二反应步骤的选择性之间的线性关系，即如果对吸附的OH的选择性提高，那么后续步骤对H2O2的选择性就会降低。我们还发现，选择性和活性呈线性比例关系，较高的活性（即较低的过电势）会导致 H2O2 形成步骤的选择性较低。根据获得的结果，几种化学物质，例如。 g.，含有 NiNx−C 部分，预计在 2e-WOR 的活性/选择性特征组合方面可与性能最佳的金属氧化物（如 ZnO 和 CaSnO3）相媲美。
A direct electrosynthesis of H2O2from either O2or H2O is an attractive strategy to replace the energy‐intensive industrial anthraquinone process. Two‐electron water oxidation reaction (2e‐WOR) offers several advantages over the oxygen reduction reaction such as better mass transfer due to the absence of gas‐phase reactants. However, 2e‐WOR is a more challenging and less studied process with only a handful of metal oxides exhibiting reasonable activity/selectivity properties. Herein, we employ density‐functional‐theory calculations to screen a variety of metal‐nitrogen‐graphene structures for 2e‐WOR. As a consequence of scaling between the adsorption energies of reaction intermediates, we determine a linear relation between selectivities for the first and second reaction steps of 2e‐WOR, viz. that if selectivity toward adsorbed OH is improved, then selectivity toward H2O2at the subsequent step is decreased. We also find that selectivity and activity are linearly scaled in such a way that a higher activity (i. e., a lower overpotential) leads to a lower selectivity for the H2O2formation step. Based on the obtained results several chemistries, e. g., containing NiNx−C moieties, are predicted to rival the best‐performing metal oxides such as ZnO and CaSnO3in terms of combination of their activity/selectivity characteristics for 2e‐WOR.