APPLIED CATALYSIS B-ENVIRONMENTAL
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2017
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IF 9.446
Wenhui Li,Xiaowa Nie,Xiao Jiang,Anfeng Zhang,Fanshu Ding,Min Liu,Zhongmin Liu,Xinwen Guo,Chunshan Song
Screening of various supports reveals that Co catalysts supported on ZrO 2 and Al 2 O 3 show good initial activity for CO 2 methanation. Co/ZrO 2 and Co/Al 2 O 3 catalysts prepared by impregnation with different metal loadings were further examined comparatively. The 10Co/ZrO 2 catalyst showed high activity with CO 2 conversion of 92.5% and CH 4 selectivity of 99.9% without deactivation after 300 h time on stream (TOS). However, the 10Co/Al 2 O 3 catalyst gave a lower CO 2 conversion of 77.8% which decreased to 38.6% after 300 h TOS. The catalysts were characterized by STEM/EDS (scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy), in situ XRD(X-ray diffractometer), H 2 -TPR(temperature programmed reduction), XPS (X-ray photoelectron spectroscopy), chemisorption of H 2 , CO, CH 4 , CO 2 and NH 3 -TPD (temperature programmed desorption). Re-dispersion of Co species on the ZrO 2 support during reduction by H 2 was observed by STEM/EDS. New Co-Zr phase formed on the Co-ZrO 2 interface was directly observed by TEM for the first time; the Co/ZrO 2 catalyst exhibited high stability with high activity for CO 2 conversion. In situ XRD, H 2 -TPR and XPS results indicate the promoting effect of ZrO 2 on the reduction of Co 3 O 4 to Co metal along with the negative effect of Al 2 O 3 . The oxygen vacancies on the ZrO 2 detected by XPS may help to activate CO 2 and H 2 O and resist deactivation. Co/Al 2 O 3 catalyst deactivates rapidly due to coke deposition and spinel formation.
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
FUEL
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2018
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IF 4.908
Zihao Zhang,Hao Chen,Changxue Wang,Kequan Chen,Xiuyang Lu,Pingkai Ouyang,Jie Fu
In this work, a series of ZrO 2 -supported Cu, Ni and bimetallic Cu-Ni catalysts were synthesized and evaluated for their activity and stability in the in situ hydrogenation and decarboxylation of oleic acid using methanol as a hydrogen donor. High-angle annular dark-field scanning transmission electron microscopy (HADDF-STEM), energy dispersive X-ray spectroscopy (EDS-mapping), X-ray diffraction (XRD) and temperature programmed reduction (TPR) characterizations revealed that the as-synthesized Cu-Ni/ZrO 2 was a Cu-Ni alloy that was highly dispersed on mixed m-ZrO 2 and t-ZrO 2 . The bimetallic Cu-Ni/ZrO 2 nanostructures not only exhibited better catalytic activity for the conversion of oleic acid compared to monometallic Cu/ZrO 2 and Ni/ZrO 2 catalysts but also demonstrated good reuse performance. The formation of the Cu-Ni alloy facilitated the decarboxylation reaction and inhibited the cracking reaction, leading to enhanced catalytic performance. The good stability of Cu-Ni/ZrO 2 was primarily due to the good hydrothermal stability of the ZrO 2 support.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2019
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IF 8.456
Shanshan Liu,Hao Wang,Ying Wei,Runduo Zhang,Sebastien Royer
ZrO2 supports, with diverse morphologies (hollow sphere, star, rod, mesoporous), were produced using hydrothermal and evaporation-induced self-assembly methods. Zirconia-supported vanadium oxide catalysts were prepared by wet impregnation and used for the low-temperature selective catalytic reduction (SCR) of NO with ammonia. Characterization of catalysts includes N2 physisorption, elementary analysis, X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed reduction by H2, and temperature-programmed desorption of NH3. Significant differences in terms of activity are measured. 3 wt % V2O5 supported on mesoporous ZrO2 (V/MZ) presents excellent N2 yields (>90%, in the 200–400 °C interval), with a wide operating temperature window (NO conversion > 95%, in the 225–425 °C interval), and less interesting performances were obtained when vanadium oxide is supported over stars, hollow spheres, and rods. Surface characterization showed a content of tetravalent vanadium ion, when supported, decreasing in the order of mesoporous > hollow sphere > star > rod. This order is in perfect agreement with the order of performance of the catalyst in the NH3-SCR reaction. The impact of tetravalent ion’s presence on the surface is confirmed by diffuse reflectance infrared Fourier transform spectroscopy analysis, Brønsted acid sites generated on the surface, and the V4+-OH species involved in the reaction. The production of more important nitrite species over the tetragonal supported vanadium oxide catalyst could be another reason for the excellent NH3-SCR performance displayed by the V/MZ catalyst. When supported over monoclinic zirconia, like vanadium oxide over star-type morphology, the adsorbed NH3 species (NH4+ and coordinated NH3) reacted with NOx adsorption species (nitrate) to form ammonium nitrate. Ammonium nitrate can be decomposed to N2 and N2O (or NO2). Thus, NO conversion curves and N2 yield curves over tetragonal zirconia (MZ) at lower temperature were ahead of those over V/star ZrO2 because of the higher V4+ surface content and more active B acid sites associated with an easy formation of the nitrito intermediate.
研究领域:
催化化学
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环境科学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
FUEL
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2022
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IF 8.035
Yangyang Liu,Baojian Chen,Rui Liu,Wenqi Liu,Xinhua Gao,Yisheng Tan,Zhenzhou Zhang,Weifeng Tu
Catalytic utilizing of CO 2 into valuable olefins on Fe-based catalysts is a feasible way to mitigate the pressure of carbon neutrality. Herein, by investigating the effects of support (SiO 2 , Al 2 O 3 , CNT, and ZrO 2 ) on the structure and catalytic performance of iron catalysts, we have found that ZrO 2 supported catalysts are more beneficial to olefin selectivity and chain growth. The optimization catalytic performance of FeNa/ZrO 2 displays C 2 -C 7 olefin selectivity of 68.2% (O/P = 8.0) with a space time yields (111.4 g Kg cat -1 h −1 ) at X CO2 = 32.7%, 320 ⁰C, 2.0 MPa, CO 2 /H 2 /Ar = 1:3:3, and 9000 mL g -1 h −1 . Characterizations show that the support regulates the composition of the iron oxide phase and the iron carbide phase and induces to form the highest content of Fe 5 C 2 on the spent FeNa/ZrO 2 , which is probably caused by the carbon rich surface and lower disorder of carbon species. Besides, the higher intensity of CO 2 and CO adsorption and lower intensity of H 2 adsorption is confirmed on the surface of the FeNa/ZrO 2 catalysts, leading to a higher ratio of C/H on the surface of the spent catalysts and consequently inhibiting the hydrogenation of olefins. Therefore, the O/P is 8 times as many as that on the FeNa/SiO 2 and FeNa/Al 2 O 3 . Understanding the effect of support on CO 2 hydrogenation to olefins over iron-based catalysts would be significant for precisely designing new catalysts.
研究领域:
催化化学
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材料科学
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环境科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2025
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IF 17.7
Zhitong Zhou,Weixiang Guan,Xiaoli Pan,Shengxin Zhang,Yang Su,Aiqin Wang,Tao Zhang
Synthesis of primary amines from alcohols is an economical and green route to access high-value N-compounds. However, challenges remain to develop both cost-effective and efficient catalysts. In this study, we developed a Ru-Co/ZrO 2 single-atom alloy catalyst which afforded diverse primary amines from alcohols in the presence of ammonia and hydrogen with exceptional conversion (up to 90%) and selectivity (80%) under mild conditions (0.7 MPa NH 3 , 0.3 MPa H 2 , 160 °C) and exhibited satisfactory stability upon regeneration. The turnover rate was approximately 8.4 times higher than that observed over the Co/ZrO 2 catalyst. Characterizations indicated that the alloyed Ru facilitated the reduction of Co, strengthened the interaction with H 2 and mitigated the over-strong adsorption of aldehyde intermediates. These combined effects contributed significantly to the enhanced catalytic performances. This work presents a promising strategy for the development of advanced catalysts in the amination of alcohols.
研究领域:
催化化学
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材料化学
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绿色化学
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有机合成
✓ 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）