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Liu Y, Ma C, Zhang J, Zhou H, Qin G, Li S. Tuning the electronic structure of Pd by the surface configuration of Al 2O 3 for hydrogenation reactions. NANOSCALE 2023; 16:335-342. [PMID: 38059873 DOI: 10.1039/d3nr05258c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
The electronic interaction between a metal and a support modulates the electronic structures of supported metals and plays an important role in manipulating their catalytic performance. However, this interaction is mainly realized in heterogeneous catalysts composed of reducible oxides. Herein, we demonstrate the electronic interaction between γ-Al2O3 and η-Al2O3 with varying acid-base properties and supported Pd nanoparticles (NPs) of 2 nm in size. The strength and number of acid-base sites on the supports and catalysts were systemically characterized by FT-IR spectroscopy and TPD. The supported Pd NPs exhibit electron-rich surface properties by receiving electrons from the electron-donating basic sites on γ-Al2O3, which are beneficial for catalyzing the hydrogenation of nitrobenzene. In contrast, Pd NPs loaded on η-Al2O3 are electron-deficient because of the rich electron-withdrawing acid sites of η-Al2O3. As a result, Pd/η-Al2O3 exhibits higher catalytic activity in phenylacetylene hydrogenation than Pd/γ-Al2O3. Our results suggest a promising route for designing high-performance catalysts by adjusting the acid-base properties of Al2O3 supports to maneuver the electronic structures of metals.
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Affiliation(s)
- Yinglei Liu
- Key Lab for Anisotropy and Texture of Materials (MoE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
| | - Chicheng Ma
- Key Lab for Anisotropy and Texture of Materials (MoE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
| | - Jiye Zhang
- Key Lab for Anisotropy and Texture of Materials (MoE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
| | - Huiying Zhou
- Key Lab for Anisotropy and Texture of Materials (MoE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
| | - Gaowu Qin
- Key Lab for Anisotropy and Texture of Materials (MoE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
- Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang 110004, China
| | - Song Li
- Key Lab for Anisotropy and Texture of Materials (MoE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.
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Li L, He Y, Xu L, Shao C, He G, Sun D, Hai Z. Oxidation and Ablation Behavior of Particle-Filled SiCN Precursor Coatings for Thin-Film Sensors. Polymers (Basel) 2023; 15:3319. [PMID: 37571213 PMCID: PMC10422518 DOI: 10.3390/polym15153319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/13/2023] Open
Abstract
Polymer-derived ceramic (PDC) thin-film sensors have a very high potential for extreme environments. However, the erosion caused by high-temperature airflow at the hot-end poses a significant challenge to the stability of PDC thin-film sensors. Here, we fabricate a thin-film coating by PDC/TiB2/B composite ceramic material, which can be used to enhance the oxidation resistance and ablation resistance of the sensors. Due to the formation of a dense oxide layer on the surface of the thin-film coating in a high-temperature air environment, it effectively prevents the ingress of oxygen as a pivotal barrier. The coating exhibits an exceptionally thin oxide layer thickness of merely 8 μm, while its oxidation resistance was rigorously assessed under air exposure at 800 °C, proving its enduring protection for a minimum duration of 10 h. Additionally, during ablation testing using a flame gun that can generate temperatures of up to 1000 °C, the linear ablation rate of thin-film coating is merely 1.04 μm/min. Our analysis reveals that the volatilization of B2O3 occurs while new SiO2 is formed on the thin-film coating surface. This phenomenon leads to the absorption of heat, thereby enhancing the ablative resistance performance of the thin-film sensor. The results indicate that the thin-film sensor exhibits exceptional resistance to oxidation and ablation when protected by the coating, which has great potential for aerospace applications.
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Affiliation(s)
- Lanlan Li
- Department of Mechanical and Electrical Engineering, School of Aerospace Engineering, Xiamen University, Xiamen 361102, China; (L.L.); (Y.H.); (L.X.); (C.S.); (G.H.)
- Fujian Micro/Nano Manufacturing Engineering Technology Research Center, Xiamen University, Xiamen 361102, China
| | - Yingping He
- Department of Mechanical and Electrical Engineering, School of Aerospace Engineering, Xiamen University, Xiamen 361102, China; (L.L.); (Y.H.); (L.X.); (C.S.); (G.H.)
- Fujian Micro/Nano Manufacturing Engineering Technology Research Center, Xiamen University, Xiamen 361102, China
| | - Lida Xu
- Department of Mechanical and Electrical Engineering, School of Aerospace Engineering, Xiamen University, Xiamen 361102, China; (L.L.); (Y.H.); (L.X.); (C.S.); (G.H.)
- Fujian Micro/Nano Manufacturing Engineering Technology Research Center, Xiamen University, Xiamen 361102, China
| | - Chenhe Shao
- Department of Mechanical and Electrical Engineering, School of Aerospace Engineering, Xiamen University, Xiamen 361102, China; (L.L.); (Y.H.); (L.X.); (C.S.); (G.H.)
- Fujian Micro/Nano Manufacturing Engineering Technology Research Center, Xiamen University, Xiamen 361102, China
| | - Gonghan He
- Department of Mechanical and Electrical Engineering, School of Aerospace Engineering, Xiamen University, Xiamen 361102, China; (L.L.); (Y.H.); (L.X.); (C.S.); (G.H.)
- Fujian Micro/Nano Manufacturing Engineering Technology Research Center, Xiamen University, Xiamen 361102, China
| | - Daoheng Sun
- Department of Mechanical and Electrical Engineering, School of Aerospace Engineering, Xiamen University, Xiamen 361102, China; (L.L.); (Y.H.); (L.X.); (C.S.); (G.H.)
| | - Zhenyin Hai
- Fujian Micro/Nano Manufacturing Engineering Technology Research Center, Xiamen University, Xiamen 361102, China
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