CATALYSIS LETTERS
·
2019
·Vol. 149
·期 7
·2004-2014
·
IF 2.372
Wang Jian,Zhao Hainan,Liu Xiaolong,Xu Wenqing,Guo Yangyang,Song Jianfei,Zhu Tingyu
In this work, we presented a detailed evaluation of Ru/TiO 2 (P25) catalysts for the catalytic oxidation of (chloro)-aromatics. The model catalysts were synthesized through wet impregnation. Catalytic evaluations, as well as ICP, BET, XRD and TEM analyses, were conducted. The results indicated that RuO 2 tended to be distributed on the rutile phase of TiO 2 , leading to an inhomogeneous distribution. These Ru/TiO 2 catalysts were very active, especially for chlorobenzene oxidation. The conversions of benzene and chlorobenzene were both suppressed by the introduction of additional water. But the amount of polychlorinated benzenes as by-products was also reduced. However, the activity of the catalyst significantly decreased with an increase in calcination temperature, suggesting that the thermal stability of the catalyst still needed to be improved. Graphical Abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
Chemistry-An Asian Journal
·
2021
·Vol. 16
·期 18
·2633-2640
·
IF 4.568
Guanghao Qiu,Qijun Pei,Yang Yu,Zijun Jing,Jintao Wang,Teng He,Ping Chen
Graphical A strategy for regulating strong metal-support interaction (SMSI) was proposed. The alkaline earth metal salts were doped into a Ru/TiO 2 catalyst, which successfully prevented the migration of TiO 2-x overlayer to Ru nanoparticles via in situ formation of titanates, while the electrons transfer from support to metal nanoparticles was strengthened. The alkaline earth metal salts-doped Ru/TiO 2 catalysts exhibited superior activity in the catalytic hydrogenation of aromatics. Classical strong metal-support interaction (SMSI) is of significant importance to heterogeneous catalysis, where electronic promotion and encapsulation of noble metal by reducible support are two main intrinsic properties of SMSI. However, the excessive encapsulation will inevitably hamper the contact between active sites and reactant, leading to reduced activity in catalysis. Herein, alkaline earth metal salts are employed to depress the encapsulation of Ru nanoparticles in Ru/TiO 2 catalyst in the present study. Thermodynamic calculation, transmission electron microscopy (TEM) and chemisorption results show that the alkaline earth metal salts could successfully prevent the migration of TiO 2-x overlayer to Ru nanoparticles in Ru/TiO 2 catalyst via in situ formation of titanates, resulting in high exposure of active metal. Meanwhile, X-ray photoelectron spectroscopy (XPS) and hydrogen temperature-programmed reduction (H 2 -TPR) results reveal that an even stronger electron donation from the reduced support to Ru nanoparticles is achieved. As a result, the alkaline earth metal salts-doped Ru/TiO 2 catalysts exhibit superior activity in catalytic hydrogenation of aromatics, which is in contrast to the pristine Ru/TiO 2 catalyst that shows negligible activity under the same conditions due to the excess encapsulation of Ru nanoparticles in Ru/TiO 2 catalyst.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2024
·
IF 5.8
Heyun Lin,Wenzhe Zhang,Huachen Shen,Hailing Yu,Yunlei An,Tiejun Lin,Liangshu Zhong
The catalytic behavior of CO hydrogenation can be modulated by metal–support interactions, while the role of the support remains elusive. Herein, we demonstrate that the presence of strong metal–support interactions (SMSI) depends strongly on the crystal phase of TiO2 (rutile or anatase) and the treatment conditions for the TiO2 support, which could critically control the activity and selectivity of Ru-based nanocatalysts for CO hydrogenation. High CO conversion and olefin selectivity were observed for Ru/rutile-TiO2 (Ru/r-TiO2), while catalysts supported by anatase (a-TiO2) showed almost no activity. Characterization confirmed that the SMSI effect could be neglected for Ru/r-TiO2, while it is dominant on Ru/a-TiO2 after reduction at 300 °C, resulting in the coverage of Ru nanoparticles by TiOx overlayers. Such SMSI could be suppressed by H2 treatment of the a-TiO2 support and the catalytic activity of the as-obtained Ru/a-TiO2(H2) can be greatly elevated from almost inactive to >50% CO conversion with >60% olefin selectivity. Further results indicated that the surface reducibility of the TiO2 support determines the SMSI state and catalytic performance of Ru/TiO2 in the CO hydrogenation reaction. This work offers an effective strategy to design efficient catalysts for the FTO reaction by regulating the crystal phase of the support.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Zhuojie Zhong,Junxuan Li,Minyin Jian,Riyang Shu,Zhipeng Tian,Chao Wang,Ying Chen,Ning Shi,Yanxue Wu
Hydrodeoxygenation (HDO) reaction is a necessary refinery process for lignin-derived phenolic compounds to be used as high quality liquid fuels. Catalyst morphology makes a big difference on the HDO performance through changing the properties of metal site and acid site, while the catalytic mechanism is still not very clear. In this work, four kinds of Ru/TiO 2 catalysts with different morphology were prepared by photochemical method and all of them achieved a high Ru metal dispersion. A series of catalyst characterizations were carried out, including XRD, BET, SEM, TEM, H 2 -TPD and NH 3 -TPD, in order to explore the crystal structure, surface property, Ru metal dispersion, hydrogen adsorption capacity as well as acid properties. Results showed that Ru/TNP catalyst possessed a large surface area, an abundance of medium strength acid sites and a good hydrogen adsorption capacity. The HDO performances on lignin-derived phenolic compounds were also compared, in which Ru/TNP catalyst presented the best HDO performance. The guaiacol conversion and the selectivity of cyclohexane product were both close to 100 % at 250 °C under 1 MPa hydrogen pressure. Moreover, the content of hydrocarbons increased from 11.1 % to 60.8 % in the lignin-oil upgrading process.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 32
·14406-14413
·
IF 3.591
Yubo Liu,Guoqiang Ding,Guoping Zhao,Haohao She,Yulei Zhu,Yong Yang
Combining glucose dehydration and the subsequent hydrogenation in one pot is a preferable approach for process development as such a method allows in situ generation of the reactive intermediate to undergo further reaction without extra energy-intensive separation. Herein, phosphotungstic acid and various types of titania (anatase, rutile, P25) supported Ru-based catalysts were considered as the dehydration and hydrogenation catalysts, respectively. Modulating the different reactant media (N2, H2), various products were obtained with GBL–H2O as the solvent. A considerable yield (42%) of levulinic acid (LA) and γ-valerolactone (GVL) (40%) were obtained in nitrogen and subsequent hydrogen. Ru/TiO2 (rutile) was the favorable hydrogenation catalyst among the three types of Ru/TiO2. Meanwhile, a certain amount of sorbitol (36%) was obtained in pure hydrogen. The hydrogenation of glucose is more likely to occur than the glucose dehydration. The physicochemical properties of the catalysts were characterized by XRD, BET, TPR, STEM and in situ CO/FT-IR, and the results show that well-dispersed Ru particles are located on the rutile crystallites, which facilitated the hydrogenation of LA. A strong metal support interaction (SMSI) was responsible for the various microstructure properties and the different hydrogenation reactivity. This work allows a better understanding of the reaction paths of glucose conversion.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）