气候变化领域集成服务门户(CCPortal): 3D porous graphitic nanocarbon for enhancing the performance and durability of Pt catalysts: A balance between graphitization and hierarchical porosity

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DOI	10.1039/c9ee01899a
	3D porous graphitic nanocarbon for enhancing the performance and durability of Pt catalysts: A balance between graphitization and hierarchical porosity
	Qiao Z.; Hwang S.; Li X.; Wang C.; Samarakoon W.; Karakalos S.; Li D.; Chen M.; He Y.; Wang M.; Liu Z.; Wang G.; Zhou H.; Feng Z.; Su D.; Spendelow J.S.; Wu G.
发表日期	2019
ISSN	17545692
起始页码	2830
结束页码	2841
卷号	12 期号:9
英文摘要	Carbon supports used in oxygen-reduction cathode catalysts for proton exchange membrane fuel cells (PEMFCs) are vulnerable to corrosion under harsh operating conditions, leading to poor performance durability. To address this issue, we have developed highly stable porous graphitic carbon (PGC) produced through pyrolysis of a 3D polymer hydrogel in combination with Mn. The resulting PGC features multilayer carbon sheets assembled in porous and flower-like morphologies. In situ high-temperature electron microscopy was employed to dynamically monitor the carbonization process up to 1100 °C, suggesting that the 3D polymer hydrogel provides high porosity at multiple scales, and that Mn catalyzes the graphitization process more effectively than other metals. Compared to conventional carbon supports such as Vulcan, Ketjenblack, and graphitized carbon, PGC provides an improved balance between high graphitization and hierarchical porosity, which is favorable for uniform Pt nanoparticle dispersion and enhanced corrosion resistance. As a result, Pt supported on PGC exhibits remarkably enhanced stability. In addition to thorough testing in aqueous electrolytes, we also conducted fuel cell testing using durability protocols recommended by the U.S. Department of Energy (DOE). After 5000 voltage cycles from 1.0 to 1.5 V, the Pt/PGC catalyst only lost 9 mV at a current density of 1.5 A cm-2, dramatically exceeding the DOE support durability target (<30 mV), and surpassing commercial Pt/C catalysts. Along with the enhanced carbon corrosion resistance of the PGC support, the enhanced catalyst-support interactions are beneficial for stability improvement, likely due to nitrogen doping into carbon, which was further elucidated through X-ray absorption spectroscopy and density functional theory (DFT) calculations. Thus, the high stability and activity of PGC-based Pt catalysts are attributed to the combination of high graphitization degree, favorable surface area and porosity, and nitrogen doping, which effectively stabilize highly dispersed Pt nanoparticles. © 2019 The Royal Society of Chemistry.
英文关键词	Carbonization; Corrosion resistance; Density functional theory; Durability; Electrolytic reduction; Graphite; Graphitization; Hydrogels; Metal nanoparticles; Nitrogen; Porosity; Porous materials; Proton exchange membrane fuel cells (PEMFC); X ray absorption spectroscopy; Flower-like morphologies; Graphitization degree; Graphitization process; Hierarchical porosity; Porous graphitic carbon; Proton exchange membrane fuel cell (PEMFCs); Stability improvement; U.S. Department of Energy; Catalyst supports; catalyst; chemical reaction; durability; nanoparticle; performance assessment; platinum; porosity; three-dimensional modeling
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/189831
作者单位	Department of Chemical and Biological Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, United States; Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, United States; Department of Physics and Engineering, Key Laboratory of Material Physics, Zhengzhou University, Zhengzhou, 450052, China; Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States; School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR 97333, United States; Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208, United States; Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261, United States; X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, United States
推荐引用方式 GB/T 7714	Qiao Z.,Hwang S.,Li X.,et al. 3D porous graphitic nanocarbon for enhancing the performance and durability of Pt catalysts: A balance between graphitization and hierarchical porosity[J],2019,12(9).
APA	Qiao Z..,Hwang S..,Li X..,Wang C..,Samarakoon W..,...&Wu G..(2019).3D porous graphitic nanocarbon for enhancing the performance and durability of Pt catalysts: A balance between graphitization and hierarchical porosity.Energy & Environmental Science,12(9).
MLA	Qiao Z.,et al."3D porous graphitic nanocarbon for enhancing the performance and durability of Pt catalysts: A balance between graphitization and hierarchical porosity".Energy & Environmental Science 12.9(2019).