Effects of Graphitic and Pyridinic Nitrogen Defects on Transition Metal Nucleation and Nanoparticle Formation on N-Doped Carbon Supports: Implications for Catalysis
Effects of Graphitic and Pyridinic Nitrogen Defects on Transition Metal Nucleation and Nanoparticle Formation on N-Doped Carbon Supports: Implications for Catalysis
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DOI：
10.1021/acsanm.2c03186
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发表时间：
2022-09
影响因子：
5.9
通讯作者：
Vu T. Nguyen;Margaret A. Fitzgerald;Denali Ibbotson;Jayson G. Foster;Michael J. Dzara;S. Zaccarine;Shubham Vyas;S. Pylypenko
中科院分区：
文献类型：
--
作者：
Vu T. Nguyen;Margaret A. Fitzgerald;Denali Ibbotson;Jayson G. Foster;Michael J. Dzara;S. Zaccarine;Shubham Vyas;S. Pylypenko
用杂原子掺杂剂官能化碳载体现在被广泛认为是稳定和加强载体与金属催化剂之间相互作用的有前途的途径。调节杂原子掺杂剂的类型和密度允许定制纳米级催化剂-载体相互作用;然而，由于系统的复杂性，对这些现象的理解尚未完全实现。在这项工作中，计算建模，材料合成和先进的纳米材料表征被用来系统地研究两个最常见的氮功能的碳基支持上的相互作用与选定的过渡金属实现催化应用的有趣的效果。具体而言，本研究利用密度泛函理论来评估吸附能量和吸附模式的12种金属位于第8-11族和周期4-6与吡啶和石墨N缺陷。基于这些结果，进一步的电子结构研究的周期4金属进行阐明周期群的趋势。实验工作包括合成和纳米材料表征的一个子集的材料具有三种金属，每种金属支持在两种类型的N-掺杂的碳载体和未掺杂的石墨烯。扫描透射电子显微镜和能量色散X-射线光谱表征的纳米材料证实，N功能增强了与所选的过渡金属的相互作用相比，未掺杂的支持，并表明，缺陷的性质影响这些相互作用。计算和实验都同意，Fe和Co偏向于吡啶的网站上的石墨网站，而镍有一个亲和力，这两个缺陷没有统计上显着的偏好。这项工作建立了计算和实验工作之间的相关性，并建立了一个框架，该框架可以扩展到其他金属和氮以外的替代掺杂剂，以定制纳米级催化剂-载体相互作用，用于广泛的催化应用。
Functionalization of carbon supports with heteroatom dopants is now widely regarded as a promising route for stabilizing and strengthening the interactions between the support and metal catalysts. Tuning the type and density of heteroatom dopants allows for the tailoring of nanoscale catalyst–support interactions; however, an understanding of these phenomena has not yet been fully realized because of the complexity of the system. In this work, computational modeling, materials synthesis, and advanced nanomaterial characterization are used to systematically investigate the intriguing effect of the two most common nitrogen functionalities in the carbon-based supports on the interactions with selected transition metals toward realizing catalytic applications. Specifically, this study utilized density functional theory to evaluate adsorption energies and modes of adsorption for 12 metals located in groups 8–11 and periods 4–6 with pyridinic and graphitic N defects. Based on these results, further electronic structure investigation of the period 4 metals was conducted to elucidate periodic group trends. Experimental work included synthesis and nanomaterial characterization of a subset of materials featuring three metals each supported on two types of N-doped carbon supports and undoped graphene. Characterization of nanomaterials with scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy confirmed that N functionalities enhanced the interactions with the selected transition metals when compared to the undoped support and demonstrated that the nature of the defect influences these interactions. Both computations and experiments agreed that Fe and Co are biased toward the graphitic sites over pyridinic sites, while Ni has an affinity to both defects without a statistically significant preference. This work established a correlation between computational and experimental work and a framework that can be expanded to other metals and alternative dopants beyond nitrogen in tailoring nanoscale catalyst–support interactions for a breadth of catalytic applications.