APPLIED CATALYSIS B-ENVIRONMENTAL
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2018
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IF 11.698
Meng Zhang,Junfeng Zhang,Yingquan Wu,Junxuan Pan,Qingde Zhang,Yisheng Tan,Yizhuo Han
Carbon deposition on the catalyst surface has been considered as one of the main reasons to cause Ni catalyst deactivation during methane reforming with carbon dioxide (DRM). Generally, it is thought that the properties and levels of coke formation are significantly affected by the ability of CO 2 adsorption and activation, which is closely related to the oxygen species over catalyst surface. In this study, the effects of oxygen species on the DRM over Ni/ZrO 2 catalysts were investigated. Wherein, ZrO 2 support was further treated under H 2 , N 2 , and O 2 atmospheres respectively to obtain different oxygen species distribution over the surface, and 3 wt.% Ni was introduced by the deposition-precipitation method. The representative samples were characterized using XRD, EPR, XPS, FTIR, TPR, TPD , TPSR, TG, Raman and TPH techniques, etc. It was found that the treatment to ZrO 2 in the reducing gas such as H 2 was able to promote the formation of adsorbed oxygen species over the surface. CO 2 DRIFTS and CH 4 -TPSR experiments further confirmed that adsorbed oxygen species were favorable for enhancing both CO 2 adsorption and activation and CH 4 dissociation. As a result, the catalyst with more adsorbed oxygen species exhibited relatively outstanding performance for the DRM and promotional ability in removal of the deposited carbon.
研究领域:
催化化学
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能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2024
·
IF 3.9
Yuhao Tian,Yixuan Li,Dong Cao,Qiying Liu,Weijie Cai
Photo-assisted ethanol dry reforming (EDR) for syngas production was deeply studied over nanorod-like Ni/ZrO 2 catalyst synthesized by precipitation and impregnation technique, respectively. The effect of light irradiation as well as catalyst preparation method on EDR reaction was investigated in detail with the stoichiometric feed ratios, over a temperature region of 350 to 550 °C. Photo-enhancement factor of ethanol conversion greatly increased from 10% (dark) to 40% (light) together with less formation of byproducts. Moreover, the experimental results depicted the better performance of P-Ni/ZrO 2 catalyst due to its abundant oxygen vacancies and strong Ni-Zr interaction. Enriched interfacial oxygen defects and more light-excited electrons facilitated the activation/dissociation of ethanol and CO 2 , thereby enhancing the catalytic activity. In addition, the mean particle size of NiO in P-Ni/ZrO 2 was (10.3 nm) which was smaller than that of the I-Ni/ZrO 2 (16.5 nm), suggesting its higher dispersion of active metal. The calculated apparent activation energy of P-Ni/ZrO 2 was 20.6 eV which was much less than the value of I-Ni/ZrO 2 (37.7 eV). This work might provide the valuable insight for the development of highly-efficient photothermal catalyst to enhance the value-added utilization of greenhouse gas CO 2 .
研究领域:
催化化学
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能源化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Fenghao Shu,Guangcai Long,Yanwu Chen,Ying Gao,Menghao Jiang,Jinxing Long
Conversion of renewable lignin to value-added aromatic chemicals presents a broad prospect to achieve the goals of “carbon neutrality”. In this work, an efficient approach is proposed for selective hydrogenolysis of lignin to valuable 4-propyl syringol in the presence of cost-effective catalyst of y Ni/ZrO 2 - x MoO 3 . When the lignin hydrogenolysis is performed with 15Ni/ZrO 2 -10MoO 3 , 15.4% yield of monophenols is achieved, which is approximately twice as that from the 15Ni/ZrO 2 catalytic system (7.8%). Importantly, 33.1% of these monophenols are identified as 4-propyl syringol (4-PS), a versatile fine chemical. An extensive characterization of the modified catalysts by means of XRD, nitrogen adsorption–desorption isotherm, SEM, TEM, XPS, NH 3 -TPD, CO 2 -TPD, and H 2 -TPR, confirms that the introduction of MoO 3 changes the primary phase of ZrO 2 and the acidity/basicity properties of catalyst. As a result, an enhanced cleavage of the C-O linkage between S-lignin and other units is demonstrated, which consequently contributes to the good selectivity of 4-propyl syringol. Therefore, this work provides a new insight for producing bulk aromatic chemicals via a sustainable route.
研究领域:
化学工程
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可再生资源利用
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产品关联
DOI
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2023
·Vol. 27
·期 4
·406-414
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IF 3
Han Yujun,Shi Yinteng,Wang Dandan,Zhou Hantao,Chen Jixiang
Ni/ZrO 2 (Ni/Zr) and Ni/WO 3 -ZrO 2 (Ni/ x WZr, x denotes WO 3 /ZrO 2 mass ratios) were prepared by the impregnation-direct reduction method and tested for the aqueous phase hydrogenation of phenol to cyclohexanone in an autoclave reactor. It has been found that the Ni-W alloy forms in Ni/ x WZr, and a charge transfer occurs from Ni to W. The presence of W species promotes the Ni dispersion and increases the amounts of acid sites and spilt-over hydrogen species. This leads to higher hydrogenation and direct deoxygenation activity of Ni/ x WZr than that of Ni/Zr. In addition, the W 6+ and W 4+ species, acted as Lewis acidic sites, may stabilize cyclohexanone and the hydrogenation of cyclohexanone to cyclohexanol is inhibited. Under suitable condition, the phenol conversion and the cyclohexanone selectivity reach 93.1 and 90.6% on Ni/0.8WZr, respectively.
研究领域:
催化
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化学反应工程
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有机化学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2025
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IF 6.3
Yonglong Huang,Zhengkang Duan,Chuan Li,Tian Qiu
The catalytic dehydrogenation of diethanolamine to prepare iminodiacetic acid has attracted considerable research interest. However, the lack of understanding of the structure-activity relationship of the reaction can present a challenge to the control of the catalytic behavior. Concurrently, improving the catalytic performance and reducing the cost have also become urgent issues that require resolution. This work examined the catalytic mechanism of several Cu-Ni X /ZrO 2 catalysts, differing in Cu/Ni ratios, prepared by H 2 reduction, in the context of DEA dehydrogenation to elucidate the structure-activity connection and probable reaction mechanism. Subsequently, a strategy has been put out to generate metal (Ni and Co)-doped copper-zirconium catalysts using the co-precipitation-hydrazine hydrate reduction process. The synergistic effect between metals was combined with the improvement of the surface reaction of the catalyst by hydrazine hydrate through a more efficient preparation method, thereby enhancing the catalyst's overall performance. The representative catalyst Cu-Ni/ZrO 2 required a hydrazine hydrate reduction temperature and time of 40 °C and 30 min, and after 65 min of reaction, it exhibited a high conversion rate (96.3 %) and yield (93.7 %), and after five cycles, both the conversion rate and yield exceeded 85 %. Various characterization techniques have confirmed that Ni doping induced an alloying effect and a size effect. Additionally, the hydrazine hydrate reduction method was discovered to augment the specific surface area, surface hydroxyl groups, hydrophilicity, and optimize the pore size distribution of the catalyst while also regularizing its morphology, thereby significantly enhancing the activity and stability of the metal-doped copper-zirconium catalyst. This paper discussed the correlation between catalyst structure and reaction performance, as well as the catalytic conversion mechanism, which is anticipated to provide a novel reference for the preparation, performance control, and potential applications of dehydrogenation catalysts.
研究领域:
催化化学
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材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2024
·
IF 5.2
Yanan Jiang,Huayu Sun,Yuzhen Fang,Cuijuan Zhang,Yuan Liu
The sintering issue of Ni nanoparticles seriously limits the practical application of the Ni-based catalysts for CO 2 methanation. This work demonstrates that the La- and Ce- dual-promoted Ni/ZrO 2 shows better durability at 600 ºC and 60000 mL g cat −1 h −1 over 200 h compared with the La- or Ce- single-promoted. The composition and microstructure characterization indicates that the dispersion and sintering resistance of Ni nanoparticles is enhanced with the dual-promoted catalysts. Both depth profile of X-ray photoelectron spectroscopy and density functional theory calculation show that in the La- and Ce- dual-promoted Ni/ZrO 2 , the reduced dissolution of Ce into ZrO 2 lattice and the spread of La on ZrO 2 surface by forming a La 2 O 3 -CeO 2 solid solution improves the dispersion and stability of Ni nanoparticles. This work provides a facile strategy to mitigate the sintering of Ni nanoparticles and thus improve the stability of Ni-based catalysts for CO 2 methanation.
研究领域:
催化
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材料科学
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化学工程
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表面科学
✓ 已验证
产品关联
DOI
高影响因子
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