INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2020
·
IF 4.939
Zhao Jiang,Xiang Gong,Shuyi Guo,Yanxin Bai,Tao Fang
The NECZ/12H-NECZ (N-ethylcarbazole/dodecahydro-N-ethylcarbazole) system is regarded as the most potential liquid organic hydrogen carrier. However, the low activity, selectivity of NECZ and high cost of catalysts for the dehydrogenation reaction restrict its efficiency and commercial applications. In this work, a series of bimetallic Pd-M(M = Cu, Ni)/SiO 2 catalysts were prepared and employed to enhance catalytic activity and selectivity of NECZ for the 12H-NECZ dehydrogenation reaction. Pd 3 Ni 1 /SiO 2 exhibited high catalytic performance with 100% conversion, 91.1% selectivity of NECZ and 5.63 wt% hydrogen release amount at 453 K, 101.325 kPa for 8 h. The TOF (turnover frequency) of Pd 3 Ni 1 /SiO 2 is enhanced by 42.4% compared with Pd/SiO 2 . Combined with the characterization analysis, it was found that adjusting the alloying degree or the alloy phase in the PdCu and PdNi bimetallic catalysts could significantly enhance the dehydrogenation activity and selectivity, which were dependent on the component of bimetallic catalysts . This work may provide theoretical guidance for designing the efficient and low-cost bimetallic catalysts for the dehydrogenation of 12H-NECZ, which could boost the commercial applications of liquid organic hydrogen carriers.
研究领域:
催化化学
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材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2014
·
IF 2.241
Keyi Wu,Yonghong Hu,Wenge Yang,Tuan Zhang,Qirun Guo,Shouhai Yang,Ying Shi
The solubility of N-Ethylcarbazole in methanol, ethanol, n-propanol, isopropanol, 1-butanol, 1-pentanol and petroleum ether was measured over the temperature range of 279.15–319.15 K at around 4 K intervals under atmospheric pressure. Experimental result showed that the solubility of N-Ethylcarbazole in seven solvents increased with the increasing temperature and they were in good agreement with the calculated solubility of the modified Apelblat equation and the λh equation. The thermodynamic properties of the solution process, including the Gibbs energy , enthalpy, and entropy were calculated by the van’t Hoff analysis. The values of both the standard molar enthalpy change and standard molar Gibbs energy change of solution were positive, which indicated that the process was endothermic.
研究领域:
物理化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2015
·
IF 2.352
Feifei Sun,Yue An,Lecheng Lei,Fuying Wu,Jingke Zhu,Xingwang Zhang
Hydrogenation of carbazole and N-ethylcarbazole over Raney-Ni catalyst were realized in the temperature range of 393–503 K. 4[H] adduct dominated the hydrogenation products and the formation of 2[H] adduct was the rate-limiting step during the period, in which the conversion of carbazole was less than 40%. The hydrogenation process followed pseudo-first-order kinetics and the hydrogenation activation energies of carbazole and N-ethylcarbazole were 90 kJ/mol and 115 kJ/mol, respectively. The reaction starting position as well as the pathway of the hydrogenation of (N-ethyl)carbazole were investigated by comparing the kinetic characteristics of hydrogen uptake of carbazole and N-ethylcarbazole. The results showed that the reaction was a stepwise hydrogenation process and the first H 2 was added to the C1 = C10 double bond in the hydrogenation.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yibo Qin,Longfei Chen,Lixia Ge,Yanfeng Zhu,Wanting Li,Xinxin Cao,Tianchang Wang,Jiong Li,Wei Han,Xinqing Chen
Hydrogen spillover plays a crucial role in heterogeneous catalysis, significantly enhancing the activity of catalysts. However, the promotion mechanism of hydrogen spillover on non-reducible oxide supports (such as zeolite) is rarely reported. Herein, we prepared Ru@Beta sample by in-situ approach, effectively encapsulating Ru species into Beta zeolite. Additionally, three samples (Ru/SiO 2 , Ru@Naβ, and Ru@Hβ) with different hydrogen spillover effect were prepared. The optimal concentration of Ru was 0.5 wt%, and the Ru@Hβ sample with the strongest hydrogen spillover has 100 % conversion rate of N-ethylcarbazole (NEC) and 98 % selectivity towards to 12H-NEC. In contrast, the Ru/SiO 2 with weak hydrogen spillover has only 89.5 % conversion rate and 28.9 % selectivity of 12H-NEC. Notably, the Ru@Hβ can still completely convert NEC even after 7 cycles, thereby exhibiting its remarkable activity and stability. Various characterizations (HAADF-STEM, XPS, EXAFS, in-situ DRIFT, and H 2 -TPD) indicate the superior catalytic performance of Ru@Hβ with strong hydrogen spillover effect, originating from the presence of more hydroxyl (–OH) and Brønsted acid on the surface, while Lewis acid act as hydrogen acceptors and NEC hydrogenation sites. This work not only expands our understanding of the hydrogen spillover, but also paves the way onto the potential applications in heterogeneous catalysis for efficient hydrogenation.
研究领域:
催化化学
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材料科学
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能源存储
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
·
IF 22.1
Wenjie Xue,Hongxia Liu,Binbin Zhao,Lixia Ge,Shuai Yang,Minghuang Qiu,Jiong Li,Wei Han,Xinqing Chen
N-ethylcarbazole (NEC) has been considered one of the most prospective liquid organic hydrogen carriers (LOHCs) for hydrogen storage. However, designing single catalyst capable of driving both hydrogenation of NEC and dehydrogenation of dodecahydro-NEC (12 H-NEC) is of a big challenge. Herein, we develop an atomic-dispersion of Rh with the Co nanoparticles (NPs) to form a Rh 1 Co structure maximizing the Rh utilization, which boosts the reversible (de)hydrogenation of NEC, and enables multiple cycles of reversible hydrogen uptake and release. Significantly, a low temperature of 90 °C is realized for the complete hydrogenation (100%), representing one of the lowest temperatures yet reported for the total hydrogenation of NEC. The remarkable catalytic performance of Rh 1 Co catalysts is the result of the optimal electronic structure between atomic-dispersion of Rh and Co NPs confirmed by structural characterizations and density functional theory (DFT) calculations, which allowed fast interfacial electron transfer to intermediates.
研究领域:
化学
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材料科学
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能源研究
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Bin Wang,Shu-han Lu,Shi-yuan Wang,Pei-ya Li,Tao Fang
N -ethylcarbazole (NEC) is a widely studied liquid organic hydrogen carrier, and a large number of catalysts with excellent reactivity has been designed and developed thus far. However, the phenomenon of isomeric transformation of 12H-NEC products during the reaction was not explained. Here, we studied the process based on three different Ru catalysts supported on zirconium-based supports, and based on the experimental results, we identified that supported metal-support strong interaction (SMSI), metal-support anion interaction (MSAI) and hydrogen spillover will have coupling effect on the hydrogenation reaction path and the occurrence of isomerization in 12H-NEC product. Higher 12 [H] B content in 12H-NEC under Ru/ZrN catalyst was caused by the large number of secondary active centers on the surface of the support reacting in the hydrogenation reaction. The active site for the isomerization of 12 [H] B to 12 [H] A may be the electronegativity interface formed by Ru and the support, while the electroneutral or electropositive interface rich in hydrogen is not conducive to the catalytic conversion. To sum up, an image model for the isomeric transformation of 12H-NEC products was proposed.
研究领域:
催化
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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
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Jihui Yao,Zhikang Xu,Shuo Cheng,Yuanyuan Yue,Haibo Zhu
The use of dodecahydro- N -ethylcarbazole in hydrogen storage for liquid organic hydrogen carrier systems holds potential for achieving large-scale application. In order to investigate the relationship between dodecahydro- N -ethylcarbazole dehydrogenation performance and Pt particles size, a series of monometallic Pt/Al 2 O 3 catalysts with different Pt particles size from 0.70 nm to 5.12 nm were controlled synthesized by a simple impregnation method. The obtained catalysts are systematically characterized via XRD, 27 Al MAS NMR, SEM-EDS, TEM, N 2 -adsorption, CO-IR, H 2 -TPR and NH 3 -TPD analyses, which provide essential micro-structure of these catalysts. The dehydrogenation of dodecahydro- N -ethylcarbazole over Pt/Al 2 O 3 is a typical consecutive reaction, which follows a reaction sequence of dodecahydro- N -ethylcarbazole → octahydro- N -ethylcarbazole → tetrahydro- N -ethylcarbazole → N -ethylcarbazole. These dehydrogenation steps are quite sensitive to the Pt particle size. Large Pt particle can greatly enhance the reaction rates in octahydro- N -ethylcarbazole → tetrahydro- N -ethylcarbazole and tetrahydro- N -ethylcarbazole → N -ethylcarbazole steps. However, these two steps are difficult to take place in small Pt particles. The high performance of large Pt particle in dehydrogenation can be ascribed to its highly exposed (1 1 1) crystal face. The optimized catalyst Pt 5.0 /γ-Al 2 O 3 with Pt average size of 4.63 nm demonstrated exceptional performance in dodecahydro- N -ethylcarbazole dehydrogenation at 180 °C and 101 kPa, and the dodecahydro- N -ethylcarbazole conversion of 100 %, N -ethylcarbazole selectivity of 96.44 % and dehydrogenation efficiency of 98.73 % can be achieved. These results provide valuable insights for the development of efficient metal-based catalysts for liquid organic hydrogen carriers hydrogen storage system.
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
FUEL
·
2022
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IF 8.035
Hu Liu,Jingwen Xue,Pengfei Yu,Yankang Zhang,Jinhua Wang,Defu Che
Hydrogen is a clean secondary energy as well as an efficient energy carrier, but the low density and small molecular hydrogen result in high economic and energetic efforts to store and transport hydrogen. In addition, the hydrogen produced by the current industry is usually impure and requires gas separation, which consequently increases the cost of hydrogen. A promising hydrogen storage technology using liquid organic hydrogen carrier (LOHC) can permit the safe storage of hydrogen for long time through the reversible chemical reaction in the presence of catalyst. The selective hydrogenation reaction of N -ethylcarbazole (NEC), an attractive LOHC compound due to the low dehydrogenation temperature of perhydro- N -ethylcarbazole (12H-NEC), with hydrogen was conducted in this study to achieve both separation and hydrogen storage for hydrogen-rich raw gas from natural gas steam reforming. First, hydrogenation experiments of molten NEC under a pure hydrogen atmosphere were carried out to determine the suitable hydrogenation conditions and reaction pathways. Then, the effect of methane addition on NEC hydrogenation was analyzed. Results indicate that there are multiple parallel pathways in the hydrogenation of NEC. The reaction rate from 8H-NEC to 12H-NEC step is extremely slow and this step is unstable at 453 K. The optimal hydrogenation temperature of NEC is 443 K and the apparent activation energy is 67.6 kJ·mol −1 . The addition of methane reduces the initial reaction rate from 0.877 g H2 ·(g Ru ·min) −1 to 0.640 g H2 ·(g Ru ·min) −1 but increases the maximum degree of hydrogenation ( DoH ) from 0.870 to 0.909.
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2014
·Vol. 32
·期 6
·1158-1163
·
IF 1.241
Yang Wenge,Wu Keyi,Hu Yonghong,Zhang Tuan,Guo Qirun,Yang Shouhai,Shi Ying
The solubility of N-ethylcarbazole in (ethanol+petroleum ether) binary solvent mixtures was measured with the temperature changing from 280.15 K to 316.15 K. The experimental data matched the solvent/Redlich-Kister (CNIBS/R-K) equation and the Jouyban-Acree equation. Computational results showed the CNIBS/R-K equation was more suitable than the Jouyban-Acree equation. The solution process in the thermodynamic properties, including the Gibbs energy, enthalpy, and entropy, was calculated by the van’t Hoff analysis.
研究领域:
化学
·
物理化学
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Ben Chen,Bowen Hui,Yuting Dong,Qiang Sheng,Xiang Li,Qinglan Hao,Chunjing Liu
The SiO 2 - and MCM-41-supported Ni catalysts were prepared by an incipient wetness impregnation method and their performance in the hydrogenation of liquid organic hydrogen carrier were evaluated using N-ethylcarbazole (NEC) as model compound. Ni particles were mainly located on the external surface of the SiO 2 -supported Ni catalysts. Both Ni particles on the external surface and filled in the mesopores of MCM-41 were found in the MCM-41-supported catalysts. The reduction of surface Ni particles occurred at low temperature (ca. 365 °C), but the complete reduction of Ni particles in the mesopores of MCM-41 required high temperature (ca. 555 °C). The MCM-41-supported Ni particles possessed lower electron densities than the SiO 2 -supported ones. The surface Ni particles showed the same activity in the hydrogenation of NEC, which were more active than those in the mesopores of MCM-41. A correlation between the electron density of Ni particles and their selectivity was observed. The higher the electron density of Ni particles, the higher the selectivity to the fully hydrogenated product (dodecahydro-N-ethylcarbazole) is.
研究领域:
催化
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 37
·27310-27322
·
IF 3.9
Zhengjian Hou,Ke Wu,Huijie Wei,Hua Chi,Yanyan Xi,Lishuang Ma,Xufeng Lin
In this study, two series of samples (rT-Pt/TiO2 prepared with a hydrogen pretreatment and Tr-Pt/TiO2 prepared with an oxygen pretreatment) were prepared by treating commercial TiO2 supports in different atmospheres to establish different TiO2 interfacial structures, followed by the addition of platinum nanoparticles (NPs) for the catalyzed hydrogenation/dehydrogenation cycle of N-ethylcarbazole (NEC). The kinetic analysis and reaction mechanism were investigated by combining XRD, Raman, CO-DRIFT, HRTEM, XPS, H2-TPD and DFT calculations. It was found that the performance of the samples for the NEC system's cyclic hydrogen storage could be modulated by treating the TiO2 interfacial structure with different atmospheres varying the extent of strong metal-support interaction (SMSI). In addition, a turnover frequency (TOF) of 191.52 min−1 for dehydrogenation was achieved at 170 °C, which is better than the previously reported catalysts. Experimental studies (characterization and kinetic studies) and DFT calculations confirmed that the SMSI of the Tr-Pt/TiO2 series samples promoted the escape of H2 and enhanced the catalytic activity for 4H-NEC in the 12H-NEC dehydrogenation reaction. In the NEC hydrogenation reaction, the rT-Pt/TiO2 series samples were pretreated with H2 before loading platinum metal, which led to the early activation of Ti4+ in their carriers, and thus suppressed the SMSI effect of the reduction process after loading platinum. This process caused the interface formed by rT-Pt/TiO2 to have a higher energy barrier to 6H-NEC, which is an intermediate product of the NEC hydrogenation process, and this interrupted the hydrogenation process of 6H-NEC.
研究领域:
催化化学
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材料科学
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理论计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Wenjie Xue,Hongxia Liu,Baohua Mao,Honglei Liu,Minghuang Qiu,Chengguang Yang,Xinqing Chen,Yuhan Sun
Hydrogen is a promising candidate to replace the exhausting fossil fuels. However, it is still a big challenge for hydrogen storage. Liquid organic hydrogen carrier (LOHC), which possesses high safety and purity, easy transport and reversibility, is highly attractive for hydrogen storage. Herein we report a new reusable bimetallic Pd-Rh nanoparticles (NPs) catalyst with synergy effect, boosting both the hydrogenation of N-ethylcarbazole (NEC) and dehydrogenation of dodecahydro-N-ethylcarbazole (12H-NEC), which allows multiple cycles of reversible high-weight% hydrogen storage and uptake in short reaction time. Various ex- and in-situ characterizations evidenced that the superior activity was attributed to the bimetallic Pd-Rh NPs cluster structure on the surface of γ-Al 2 O 3 support. The mechanism of NEC hydrogenation over the Pd-Rh catalyst was proposed and verified by density functional theory (DFT) calculations. Such a strategy can be extended to other LOHCs and sheds light onto the development of LOHCs as energy vectors.
研究领域:
化学工程
·
材料科学
·
能源技术
✓ 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）