APPLIED SURFACE SCIENCE
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2022
·
IF 7.392
Shuibo Wang,Chunzheng Wu,Hongbo Yu,Yuting Chu,Shiwei Wang,Tong Li,Hongfeng Yin
Tailoring the interface between active metals and promoters to improve catalytic performance is a challenging issue for bicomponent catalysts. Herein, we developed a series of silica supported Pt-CoO x hybrid nanocatalysts though in situ oxidation of supported bimetallic PtCo nanoparticles (NPs) with different Pt/Co ratios. Focusing on the hydrogenation of acetophenone to 1-phenylethanol as the model reaction, the obtained Pt-CoO x /SiO 2 catalysts showed superior activity and selectivity compared to Pt/SiO 2 , and the sample with a Co/Pt molar ratio of 1/3 performed the best. Our research showed that the CoO x on Pt not only changed its electronic and geometric properties, but also promoted the adsorption of reactants and the dissociation of H 2 . A further increase of the Co/Pt ratio to 1/1, however, reduced the activity due to blockage of the Pt surface.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of CO2 Utilization
·
2025
·
IF 8.4
Heng-Bo Zhang,Guo-Qing Yang,Jiageng Li,Zhong-Wen Liu
Transition metal is quantitatively investigated as a promoter of Pt-supported catalysts for the oxidative dehydrogenation of propane with CO 2 (CO 2 -ODP). However, the criteria for selecting the transition metal are largely from trial and error. In this work, Pt/SiO 2 catalysts promoted with 3d transition metals (TMs) of Mn, Fe, Co or Ni (PtTM/SiO 2 ) are comparatively studied for CO 2 -ODP. We found that the C 3 H 6 selectivity and conversions of propane and CO 2 are clearly improved when TMs are introduced into Pt/SiO 2 . Moreover, the apparent activation energy for the C 3 H 6 formation during CO 2 -ODP is decreased in the order of PtNi/SiO 2 > PtCo/SiO 2 > PtFe/SiO 2 > PtMn/SiO 2 . Among the investigated catalysts, PtMn/SiO 2 is the most active and selective catalyst for the activation of C-H bonds in propane to produce C 3 H 6 while PtNi/SiO 2 is the most favorable catalyst for the formation of by-products via the dry reforming of propane with CO 2 and propane cracking. Essentially, the catalytic results are well explained as the increased electron density of Pt over the PtTM/SiO 2 catalysts via the enhanced electron transfer from TM having a smaller electronegativity. This understanding is important for the rational design of a high-performance Pt-based bimetallic catalyst for CO 2 -ODP.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2017
·Vol. 7
·期 13
·2717-2728
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IF 5.773
Chaoquan Hu,Jiahan Sun,Dongjuan Kang,Qingshan Zhu,Yafeng Yang
Gas-phase hydrogenation of 1,3-butadiene was investigated over Pt/SiO2 catalysts with the aim of understanding the complete hydrogenation of dienes. The measurements focused on the effect of Pt dispersion on the product distribution and the kinetics of n-butane formation. Under the investigated conditions with an excess of hydrogen, the selectivity to n-butane sharply decreased from 41.6% to less than 3% at a 1,3-butadiene conversion of ∼10% when the average Pt particle size increased from 3.9 to 22 nm. Correspondingly, the apparent activation energy for n-butane formation was measured to increase by about 2.7 times. In situ diffuse reflectance infrared Fourier transform (DRIFT) observations via alternating 1,3-butadiene and hydrogen feeds over the catalysts demonstrated that 1-butene was the major reaction intermediate in the process of 1,3-butadiene hydrogenation. By analysis of the kinetic data using the Horiuti–Polanyi mechanism with 1-butene as the intermediate, different reactivities of hydrogen on the catalysts towards CC bond hydrogenation were proposed to understand the variation of the selectivity to n-butane with Pt dispersion. This viewpoint was further supported by DFT calculation of 1-butene hydrogenation with hydrogen at different sites on the Pt(111) surface.
研究领域:
催化化学
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材料科学
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表面科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Jingyi Wang,Guangzhi He,Chunying Wang,Xudong Chen,Xiaofeng Liu,Yaobin Li,Wenpo Shan,Hong He
Modulating the electronic metal-support interaction (EMSI) is one of the effective means to promote catalytic activity because it can adjust the electron occupancy of the d -band of noble metals, further facilitating the activation of reactants. Herein, we prepared a Pt/SiO 2 catalyst with an ultralow Pt loading of 0.05% and found that its catalytic activity in HCHO oxidation outperformed that of the Pt/TiO 2 counterpart, owing to the EMSI effect between Pt and SiO 2 . On this basis, the alkali metal Na was used as a promoter, and the formation of highly active Pt-O x (OH)-Na clusters enabled the complete oxidation of HCHO at room temperature. With ultralow Pt loading, the Pt-Na/SiO 2 catalyst reduces the cost of practical application remarkably. In situ DRIFTS and DFT calculations confirmed that the reaction pathways were distinct on Pt/SiO 2 and Pt-Na/SiO 2 . Specifically, on Pt-Na/SiO 2 , the reaction follows the mechanism of the direct degradation of formate species with the assistance of active hydroxyls; while on Pt/SiO 2 , CO is the only intermediate formed by the dehydrogenation of HCHO, due to the lack of active hydroxyls. These findings provide new insights into the reaction pathway of HCHO oxidation.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2024
·
IF 7.4
Jinglei Cui,Yujun Cui,Jingjing Tan,Huirong Zhang,Mengyuan Gu,Long Huang
Volatile organic compounds (VOCs) are one of the main pollutants produced in industrial processes. Catalytic oxidation is an effective method to eliminate VOCs, and the key lies in designing efficient metal catalyst. In this work, Pd-Pt/SiO 2 bimetallic catalysts were designed and prepared by the immobilization method, and their performances for toluene oxidation were evaluated. The addition of Pt into the catalyst elevated markedly the reduction of Pd active sites, leading to abundant electron-deficient Pd 0 and electron-rich Pt 0 in the Pd 2 Pt 1 catalyst, which were confirmed by TEM, CO pulse adsorption and in-situ XPS. As revealed by O 2 -TPD and toluene-TPD characterization, the cooperative effect of electron-deficient Pd 0 and electron-rich Pt 0 in Pd 2 Pt 1 catalyst facilitated the activation of O 2 and toluene, thus enhanced greatly its activity. A conversion of 90% (T 90 ) for toluene was achieved over Pd 2 Pt 1 catalyst at 165 ℃, and the apparent activation energy ( E a ) over Pd 2 Pt 1 catalyst was lower than that over other Pd-Pt bimetallic and monometallic Pd or Pt catalysts. Additionally, the reaction mechanism was studied by In - situ DRIFTS, the results showed that the toluene oxidation passed successively benzyl alcohol, benzaldehyde, benzoic acid and maleic anhydride , then maleic anhydride was further oxidized to CO 2 and water.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
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