Theoretical Insights into Dual-Metal-Site Catalysts for the Nonoxidative Coupling of Methane,ACS Catalysis

当前位置： X-MOL 学术 › ACS Catal. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Theoretical Insights into Dual-Metal-Site Catalysts for the Nonoxidative Coupling of Methane
ACS Catalysis ( IF 11.3 ) Pub Date : 2021-10-14 , DOI: 10.1021/acscatal.1c02597
Zheng-Qing Huang ₁ , You-Tao Chen _{1,

2} , Chun-Ran Chang ₁ , Jun Li _{3,

4}

Affiliation

Direct conversion of methane to C₂ hydrocarbons under nonoxidative conditions is an attractive technology but is challenging due to high reaction temperature, severe coke deposition, and low selectivity. Here, we report three dual-metal-site catalysts (DMSCs) based on nitrogen-doped graphene (FeCo–N–C, Fe₂–N–C, and Co₂–N–C) for nonoxidative coupling of methane to C₂ hydrocarbons from a theoretical perspective. Our calculated results reveal that DMSCs present universally better performance in methane activation than single-metal-site catalysts (Fe–N–C and Co–N–C). Among the three DMSCs, Co₂–N–C exhibits the best catalytic activity and superior selectivity to ethane in the whole reaction pathway. Our microkinetic modeling reveals that the Co₂–N–C catalyst can convert methane to CH₃, C₂H₆, and H₂ at 1200 K. The electronic structure analysis and ab initio molecular dynamics simulations demonstrate that Co₂–N–C possesses both intrinsic stability and high-temperature stability. Moreover, Co₂–N–C also manifests better coke resistance compared with larger Co clusters, indicated by the difficult kinetics of methane deep dehydrogenation to naked carbon. This work provides a potential catalyst prototype for the selective conversion of methane to C₂ hydrocarbons under nonoxidative conditions.

中文翻译：

用于甲烷非氧化偶联的双金属位点催化剂的理论见解

在非氧化条件下将甲烷直接转化为 C ₂烃是一项有吸引力的技术，但由于反应温度高、焦炭沉积严重和选择性低而具有挑战性。在这里，我们报告了三种基于氮掺杂石墨烯（FeCo–N–C、Fe ₂ –N–C 和 Co ₂ –N–C）的双金属位点催化剂（DMSCs），用于甲烷与 C _{2 的}非氧化偶联从理论角度看碳氢化合物。我们的计算结果表明，与单金属位点催化剂（Fe-N-C 和 Co-N-C）相比，DMSCs 在甲烷活化方面表现出普遍更好的性能。在三个 DMSC 中，Co ₂-N-C在整个反应途径中表现出最好的催化活性和对乙烷的优异选择性。我们的微动力学模型表明，Co ₂ -N-C 催化剂可以在 1200 K 下将甲烷转化为 CH ₃、C ₂ H ₆和 H _2。电子结构分析和从头算分子动力学模拟表明 Co ₂ -N-C兼具内在稳定性和高温稳定性。此外，Co ₂与较大的 Co 簇相比，–N–C 还表现出更好的抗焦炭性，这由甲烷深度脱氢成裸碳的困难动力学表明。这项工作为在非氧化条件下将甲烷选择性转化为 C ₂烃提供了一种潜在的催化剂原型。

更新日期：2021-11-05

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11