Controlled One‐pot Synthesis of Nickel Single Atoms Embedded in Carbon Nanotube and Graphene Supports with High Loading
| Autor: | Martin Saunders, Lichang Yin, San Ping Jiang, Bernt Johannessen, Chang Liu, Shiyong Zhao, Qianfan Zhang, Roland De Marco, Guangmin Zhou, Shize Yang, Tianshuai Wang, Jean-Pierre Veder, Liji Zhang, Chao Lin |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Graphene Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology Carbon nanotube 010402 general chemistry 021001 nanoscience & nanotechnology Microstructure 01 natural sciences 0104 chemical sciences law.invention Catalysis Biomaterials Nickel Amorphous carbon chemistry Chemical engineering law Materials Chemistry 0210 nano-technology Pyrolysis Electrochemical reduction of carbon dioxide |
| Zdroj: | ChemNanoMat. 6:1063-1074 |
| ISSN: | 2199-692X |
| Popis: | Single-atom catalysts (SACs) have attracted much attentions due to the advantages of high catalysis efficiency and selectivity. However, the controllable and efficient synthesis of SACs remains a significant challenge. Herein, we report a controlled one-pot synthesis of nickel single atoms embedded on nitrogen-doped carbon nanotubes (NiSA−N−CNT) and nitrogen-doped graphene (NiSA−N−G). The formation of NiSA−N−CNT is due to the solid-to-solid rolling up mechanism during the high temperature pyrolysis at 800 °C from the stacked and layered Ni-doped g-CN, g-CN−Ni structure to a tubular CNT structure. Addition of citric acid introduces an amorphous carbon source on the layered g-CN−Ni and after annealing at the same temperature of 800 °C, instead of formation of NiSA−N−CNT, Ni single atoms embedded in planar graphene type supports, NiSA−N−G were obtained. The density functional theory (DFT) calculation indicates the introduction of amorphous carbon source substantially reduces the structure fluctuation or curvature of layered g-CN-Ni intermediate products, thus interrupting the solid-to-solid rolling process and leading to the formation of planar graphene type supports for Ni single atoms. The as-synthesized NiSA−N−G with Ni atomic loading of ∼6 wt% catalysts shows a better activity and stability for the CO reduction reaction (CORR) than NiSA−N−CNT with Ni atomic loading of ∼15 wt% due to the open and exposed Ni single atom active sites in NiSA−N−G. This study demonstrates for the first time the feasibility in the control of the microstructure of carbon supports in the synthesis of SACs. |
| Databáze: | OpenAIRE |
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