CATALYSIS LETTERS
·
2019
·Vol. 149
·期 4
·1007-1016
·
IF 2.372
Liu Pengcheng,Niu Ruyue,Li Wei,Wang Shuang,Li Jinping
Three Ru/CeO 2 catalysts with different morphologies of CeO 2 (cube spheres, microspheres and nano rods) were used to evaluate the support-morphology-dependent ammonia synthesis activity. Catalytic experiments show that the Ru/CeO 2 –CS catalyst has higher catalytic activity (27,000 µmol g −1 h −1 ) than Ru/CeO 2 –MS (21,000 µmol g −1 h −1 ) and Ru/CeO 2 –NR (15,000 µmol g −1 h −1 ) under the reaction conditions of 450 °C, 3 MPa, H 2 /N 2 = 3:1 (60 mL min −1 ). The transmission electron microscopy analysis showed that the dispersion of active metal Ru is affected by the morphology of CeO 2 . Brunauer–Emmett–Teller indicates that the 3–5 nm the pore size of CeO 2 supports contributes to the active metal Ru enters the pores of the CeO 2 support, which improves the dispersion of Ru and prevents the sintering and agglomeration of Ru in some extent. TPR studies shown that the reduction of ruthenium oxide is influenced by the morphology of CeO 2 . XPS and CO 2 -TPD demonstrated that the Ru/CeO 2 –CS catalyst exhibited higher surface oxygen vacancies, higher basic site density and lower Ru binding energy, indicating that Ru nanoparticles in Ru/CeO 2 –CS is more electron-rich and are more capable of back-donating electrons to adsorbed N 2 and subsequently activate N 2 . Our results indicate that the morphology effect of the CeO 2 supports on the Ru/CeO 2 catalyst is related to the pore size distribution and the surface oxygen vacancies of the CeO 2 supports, ratio of Ru n+ , basic site density. Graphical Abstract
The CeO 2 –CS (cube spheres) morphology facilitated the dispersion of the active metal Ru and the 3 nm the pore size of CeO 2 –CS contributed to the Ru enters the pores of the support. And the Ru/CeO 2 –CS catalyst exhibited higher surface oxygen vacancies and lower Ru binding energy, which enhanced the adsorption of hydrogen and nitrogen species and thus weakened the N≡N bond.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 102
·99842-99850
·
IF 3.289
Kun Zhang,Xu Zhang,Tianwei Tan
In this study, the conversion from Botryococcus braunii liquid to bio-jet fuel via a Ru/CeO2 catalyst was conducted. At first, novel Ru/CeO2 catalysts were prepared in order to increase the catalytic activity. “Ru/CeO2-alcohol thermal” showed the highest activity: the squalane conversion exceeded 90%, an increase of about 22% in comparison with “Ru/CeO2-impregnation”. When the B. braunii liquid was used as the raw material, no obvious catalytic activity was noticed. Therefore, the influence of impurities in the B. braunii liquid on the Ru/CeO2 reaction were preliminarily analysed, confirming that the pigments (such as β-carotenoid) and the oxygen compounds (such as fatty acids) were the main factors influencing the Ru/CeO2 reaction. Based on these results, the reaction process was optimized: prolonging the reaction time and pretreating the B. braunii liquid with H2. Finally, the production of bio-jet fuel over Ru/CeO2 was successfully achieved.
研究领域:
生物技术
·
催化化学
·
可再生能源
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DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Jiabing Chen,Yibo Tang,Xingmao Jiang,Rui Zhang,Xiaojun Lu
In this work, Ru–CeO2 prepared by a “melting” method and used as a heterogeneous catalyst for ethylene methoxycarbonylation was investigated, together with two other catalysts prepared by impregnation and aerosol methods. The Ru–CeO2 (1%-M) catalyst demonstrates activity significantly higher than that of the other catalysts with the same Ru content. The XPS and Raman analysis results suggest that the Ru–CeO2 (1%-M) oxygen vacancy content is not the highest among the catalysts prepared using the three methods, even though the content oxygen vacancies have been reported to play a crucial role in carbonylation when using a Ru–CeO2 catalyst. It was discovered that the available Ru0 (Ru0 in the freshly prepared sample plus that being transformed from Run+ during reduction) is the other decisive factor in determining the catalyst’s performance. We further investigated the high reducibility of the catalyst prepared by using the melting method and discovered that a weak metal–support interaction could be obtained because of the independent formations of Ru and CeO2 crystals with graphite carbon as the barrier. Removing carbon under the optimal conditions could facilitate the as-formed Ru crystals anchored onto CeO2; therefore, there is no strong interaction between Ru and CeO2.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2019
·
IF 2.155
Wei Li,Pengcheng Liu,Ruyue Niu,Jinping Li,Shuang Wang
Three CeO 2 supports with different concentration of surface oxygen vacancies were prepared by using C 12 H 29 NO (TPAOH), C 2 H 8 N 2 (EDA) and NaOH as precipitant under hydrothermal conditions, respectively. Catalytic experiments showed that the Ru/CeO 2 -TPAOH catalyst has superior catalytic activity (22000 μmol g −1 h −1 ) than Ru/CeO 2 -EDA (19000 μmol g −1 h −1 ) and Ru/CeO 2 –NaOH (16500 μmol g −1 h −1 ) at 450 °C, 3 MPa. In addition, the introduction of Cs and Ba promoters improve the catalytic activity of the Ru/CeO 2 -TPAOH. However, the introduction of K promoter inhibits the catalytic activity of the Ru/CeO 2 -TPAOH. The 4% Cs promoter can effectively increase the catalytic activity of the Ru/CeO 2 -TPAOH (32000 μmol g −1 h −1 ). BET and TEM indicated that 5.5 nm average pore size of CeO 2 -TPAOH support contributes to the dispersion of active metal Ru. XPS and CO 2 -TPD proved that the Ru/CeO 2 -TPAOH catalyst has higher Ce 3+ concentration, more oxygen vacancies, and higher basic site density, which are important factors for improving ammonia synthesis activity.
研究领域:
化学工程
·
材料科学
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DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Dongyang Yang,Bingxiao Feng,Hongxin Wang,Qingjuan Xie,Yaping Liu,Hengjun Gai,Hongbing Song
Selective oxidation of alcohols to aldehydes by molecular oxygen is one of the most important transformations in multiphase catalysis. In this paper, a catalyst with selective oxidation ability was designed and synthesized for the selective catalytic oxidation of benzyl alcohol. N-doped carbon materials were prepared by high-temperature calcination using hydrothermal reaction products of citric acid and melamine as a carbon source, and a bimetallic catalyst supported by Ru-CeO 2 was constructed using the mixture as the carrier for the selective oxidation of benzyl alcohol to benzaldehyde. The results showed that the introduction of CeO 2 could effectively improve the oxidizing ability and catalytic activity of the catalyst. The Ru-Ce 0.05 /NC170–600 catalyst was able to convert 85.5 % benzyl alcohol into benzaldehyde at 140 °C, 6 h, and 2 MPa, and the selectivity for benzaldehyde was 100 %. It was demonstrated by DFT that it was theoretically feasible to generate benzaldehyde by extracting hydrogen atoms from benzyl alcohol molecules. Further, the selective oxidation experiments on other alcohols showed that the catalyst has high activity for the oxidation of various alcohols to generate the corresponding carbonyl products, and it is a catalyst with broad-spectrum selective oxidation ability. In this study, a green synthesis route of benzaldehyde was proposed to solve the problems in the traditional process. Meanwhile, it provides a new idea for the synthesis of carbonyl products by selective oxidation of alcohols.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Zhen-Yu Zhang,Tao Xie
Solar-driven photo-thermal dry reforming of methane (DRM) is an environmentally friendly production route for high-value-added chemicals. However, the lack of thorough understanding of the mechanism for photo-thermal reaction has limited its further development. Here, we systematically investigated the mechanism of photo-thermal DRM reaction with the representative of Ru/CeO 2 catalyst. Through in situ DRIFTs and transient experiments, comprehensive investigation into the reaction steps and their reactive sites in the process of DRM reaction were conducted. Besides, the excitation and migration direction of photo-electron was determined by ISI-XPS experiments, and the change of surface defect structure induced by light was characterized by ISI-EPR experiments. Based on the above results, the photo-enhancement effect on each micro-reaction step was determined. This study provides a theoretical basis for the industrialization of photo-thermal DRM reaction and its development of catalysts.
研究领域:
化学工程
·
催化科学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yi-Ran Du,Yi-Yu Tao,Jing-Wen Sun,Han-Sheng Li,Rui Zhang,Bao-Hua Xu
Despite great progress on the heterogeneous catalytic methoxycarbonylation of alkenes, the research on long-chain substrates is yet undeveloped. In this study, an efficient protocol was built by introducing 1-butyl-3-methylimidazole chloride (BmimCl) additive to the catalytic system of ceria-supported Ru clusters (Ru-CeO 2 ), providing the aliphatic esters with yields over 80 %. Experimental results combined mechanism studies demonstrated that the adsorption of chloride ion at oxygen vacancy (Vö) of CeO 2 during the catalysis delivered surfaces with reduced local concentration of Vö and electron-richer Ru sites. The synergistic effect between Vö and chloride ion boosted methanol (CH 3 OH) dissociation, providing higher coverage of dissociated CH 3 O species with lower adsorption energy and thereby accelerating the rate-limiting step of methoxycarbonylation. Importantly, the β-H elimination for competitive isomerization process was greatly inhibited on the electron-richer Ru sites. Meanwhile, the side hydrogenation was further suppressed by the restrained freedom of adsorbed H at such surfaces. These positive effects jointly offer a heterogeneous catalytic system of both efficient and selective on the challenging long-chain alkene substrates, taking methyl-4-pentenoate and chain alkenes with 6, 8, 10 and 12 carbon atoms as examples.
研究领域:
多相催化
·
有机合成
·
表面化学
·
材料科学
·
化学反应工程
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产品关联
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Zhiyuan Kong,Sibao Liu,Hongwang Liu,Guozhu Liu
Endothermic hydrocarbon fuel is the most utilized coolant in regenerative cooling technology for the high-speed aircraft, but it is challenged by the limited heat sink and severe coke deposition. In this study, we propose liquid ammonia as a promising carbon-free fuel with high heat sink for advanced vehicles or aircrafts. The chemical heat sink originates from the endothermic decomposition reaction of ammonia. A series of Ru/CeO2–Al2O3 catalytic coatings were fabricated on stainless-steel tubes using the washcoating method to catalyze the ammonia decomposition reaction and enhance chemical heat sink. The catalytic performance of these Ru/CeO2–Al2O3 coatings for ammonia decomposition was evaluated using an electrically heated tubular reactor. With the Ru/CeO2–Al2O3 coatings of 19 μm, ammonia conversion reaches up to 65%, and a remarkable high heat sink of 5.9 MJ/kg was achieved at 800 °C and 5 MPa. This value is ca. 68% higher than that of the typical hydrocarbon fuel JP-7. This work shows that liquid ammonia can serve as a novel generation high heat sink fuel for advanced engines and aircrafts.
研究领域:
航空航天工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Jiabing Chen,Xiaowei Zhu,Mengheng Wang,Xingmao Jiang,Xiaojun Lu
The reaction rate of alkoxycarbonylation is typically lower when using heterogeneous catalysts compared to homogeneous catalysis, primarily due to the reduced ability of the active sites to activate the reactants. To address the insufficient activation of reactants on the Ru/CeO 2 catalyst for ethylene methoxycarbonylation, this study investigates the doping of CeO 2 with Pr 3+ ions. By substituting Ce 4+ with Pr 3+ in the CeO 2 , richer oxygen vacancies are generated, which enhance the activation of CH 3 OH. This doping significantly increases the reaction rate of ethylene methoxycarbonylation to methyl propionate (MP), achieving a rate of 86.1 g·g Ru -1 ·h −1 while maintaining a selectivity of over 99 %. Notably, Pr doping also induces the formation of Ru-O-Ce species in the catalyst, which hinders the reduction of Ru species. However, this hindered reduction is counterbalanced by the enhanced dispersion of Ru species, as Pr doping promotes the formation of smaller Ru nanoparticles. Thus, an optimal level of Pr doping exerts a synergistic effect by positively influencing both the CeO 2 support and the Ru metal, thereby improving their respective abilities to activate the reactants and enhancing the overall performance in the ethylene methoxycarbonylation reaction to produce MP.
研究领域:
催化
·
材料科学
·
化学反应工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Long Xie,Bin Hu,Riyang Shu,Zhipeng Tian,Ying Chen,Chao Wang
Methanol reforming has been a popular pathway to produce hydrogen due to the high hydrogen storage density of methanol. CeO 2 as the support is widely used for catalytic methanol reforming, but the effect of CeO 2 morphology on the reaction mechanism has not been revealed out. In this study, the catalytic performances of Ru/CeO 2 with different CeO 2 morphology, including rod , cubic and their mixed, were investigated in methanol reforming for the production of hydrogen. By regulating the temperature during hydrothermal preparation, different CeO 2 supports can be achieved. Results showed that Ru/CeO 2 catalyst with rod CeO 2 (Ru/r-CeO 2 ) exhibited a much better catalytic performance than the cubic catalyst (Ru/c-CeO 2 ) and the mixed catalyst (Ru/m-CeO 2 ), with a higher yield of hydrogen and a lower selectivity of CO product. This was mainly due to the large surface area that favored the dispersion of Ru metal site and the interaction between Ru and CeO 2 support that improved the electron transfer to benefit the formation of oxygen vacancy . Therefore, the Ru/r-CeO 2 catalyst possessed abundant oxygen vacancy , which enabled to adsorb the methanol efficiently and trigger the methanol reforming reaction . It also can enhance the adsorption of CO and water and promote the water-gas-shift reaction to increase the yield of hydrogen production .
研究领域:
催化化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Zong Hu,Zheng Wang,Yun Guo,Li Wang,Yanglong Guo,Jinshui Zhang,Wangcheng Zhan
Ruthenium (Ru) nanoparticles (∼3 nm) with mass loading ranging from 1.5 to 3.2 wt % are supported on a reducible substrate, cerium dioxide (CeO2, the resultant sample is called Ru/CeO2), for application in the catalytic combustion of propane. Because of the unique electronic configuration of CeO2, a strong metal–support interaction is generated between the Ru nanoparticles and CeO2 to stabilize Ru nanoparticles for oxidation reactions well. In addition, the CeO2 host with high oxygen storage capacity can provide an abundance of active oxygen for redox reactions and thus greatly increases the rates of oxidation reactions or even modifies the redox steps. As a result of such advantages, a remarkably high performance in the total oxidation of propane at low temperature is achieved on Ru/CeO2. This work exemplifies a promising strategy for developing robust supported catalysts for short-chain volatile organic compound removal.
研究领域:
催化化学
·
环境化学
·
材料科学
·
多相催化
·
能源与燃料
✓ 已验证
DOI
高影响因子
Energy Sources Part A-Recovery Utilization and Environmental Effects
·
2019
·
IF 0.894
Pengcheng Liu,Ruyue Niu,Wei Li,Shuang Wang,Jinping Li
In this essay, the effect of the morphology of the CeO2 support and the Ba promoter on the ammonia synthesis reaction was studied. CeO2 support with {110} and {100} crystal planes and more oxygen vacancies enhanced the catalytic activity of ammonia synthesis. The relatively uniform microspheres structure CeO2 support (CeO2-MS) with {110} and {100} crystal planes was synthesized. The structural functions of the as-synthesized CeO2 support for the Ru-based catalyst were investigated in the ammonia synthesis reaction. The results of catalytic performance showed that the catalytic activity of 2.5%Ru/CeO2-MS catalyst reached 8940 μmol· g−1· h−1 at 450 ℃, 3.8 MPa, H2/N2 = 3 (60 mL∙min−1), which is higher nearly 2.5 times than the 2.5%Ru/CeO2-commercial (CeO2-C). And the catalytic activity of catalysts increased with the increase of reaction temperature. The activity of 6%Ba-2.5%Ru/CeO2-MS (24000 μmol· g−1· h−1) catalyst increased about 268% than that of catalyst without addition of Ba. Their physical and chemical properties were characterized by XRD, BET, HRTEM, H2-TPR, H2-TPD, and XPS analyses. Our results indicate that the 2.5%Ru/CeO2-MS catalyst and catalysts involving promoters (Cs, K, and Ba) exhibit significant support-morphology-dependent catalytic activity for ammonia synthesis.
✓ 已验证
DOI
高影响因子
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