JOURNAL OF ORGANOMETALLIC CHEMISTRY
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2024
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IF 2.1
Yu Wei,Yingxia Wu,Xuejin Li,Juan Zhang,Honghong Chang,Wenchao Gao,Fanhui Meng,Peng Yang
This paper report a cost-effective, green, and acceptorless dehydrogenative one-pot synthesis of indole derivatives from ethylene glycol and aniline derivatives using an acidic alumina-supported Pt nanoparticle catalyst (Pt/Al 2 O 3 ) with 3 wt% Pt loading. The indole yield could reach more than 50 %, which was further expanded to synthesize eight indole derivatives including 5-methoxyindole. Catalyst characterisation showed that Pt/Al 2 O 3 was weakly acidic catalyst, the Pt particles were highly dispersed in nano-size on the surface of the Al 2 O 3 . The mechanistic studies shows that the indoles proceeded via successive dehydrogenation, condensation and dehydration steps with high showed atomic efficiency, with N -(2-Hydroxyethyl) aniline as the key intermediate, and N,N' -diphenylethylenediamine and 1,4-diphenylpiperazine as the main by-products.
研究领域:
有机化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
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2015
·Vol. 44
·期 41
·18012-18018
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IF 4.197
Yongfeng Liu,Yaxiong Yang,Xin Zhang,You Li,Mingxia Gao,Hongge Pan
The thermal dehydrogenation process of the KOH-containing Mg(NH2)2–2LiH system was systematically investigated by identifying changes in the structure and composition of its components by XRD and FTIR. During ball milling, the added KOH reacts with Mg(NH2)2 and LiH to produce MgO, KH and Li2K(NH2)3. During the initial heating process (<120 °C), the newly formed KH and Li2K(NH2)3 react with Mg(NH2)2 and LiH to yield MgNH, LiNH2 and Li3K(NH2)4 along with hydrogen release. Raising the temperature to 185 °C results in a reaction between Mg(NH2)2, MgNH and LiH that gives Li2Mg2N3H3 as the product and further releases hydrogen. As the temperature is increased to 220 °C, Li2Mg2N3H3 reacts with LiNH2 and LiH to produce Li2MgN2H2 and H2. Meanwhile, two parallel reactions between Li2Mg2N3H3, Li3K(NH2)4 and LiH also generate additional hydrogen. Specifically, the KH and Li2K(NH2)3, formed in situ during ball milling, serve as reactants in the dehydrogenation reaction of the Mg(NH2)2–2LiH system, which is responsible for the significantly improved thermodynamics and kinetics of hydrogen storage.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
ACS Catalysis
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2019
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IF 12.221
Jiayun Zhang,Yuchen Deng,Xiangbin Cai,Yunlei Chen,Mi Peng,Zhimin Jia,Zheng Jiang,Pengju Ren,Siyu Yao,Jinglin Xie,Dequan Xiao,Xiaodong Wen,Ning Wang,Hongyang Liu,Ding Ma
Tin-assisted fully exposed Pt clusters are fabricated on the core–shell nanodiamond@graphene (ND@G) hybrid support (a-PtSn/ND@G). The obtained atomically dispersed Pt clusters, with an average Pt atom number of 3, were anchored over the ND@G support by the assistance of Sn atoms as a partition agent and through the Pt–C bond between Pt clusters and defect-rich graphene nanoshell. The atomically dispersed Pt clusters guaranteed a full metal availability to the reactants, a high thermal stability, and an optimized adsorption/desorption behavior. It inhibits the side reactions and enhances catalytic performance in direct dehydrogenation of n-butane at a low temperature of 450 °C, leading to >98% selectivity toward olefin products, and the turnover frequency (TOF) of a-PtSn/ND@G is ∼3.9 times higher than that of the traditional Pt3Sn alloy catalyst supported on Al2O3 (Pt3Sn/Al2O3).
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
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IF 22.1
Nanxing Gao,Dongchen Han,Tongtong Yang,Qinglei Meng,Xian Wang,Changpeng Liu,Junjie Ge,Wei Xing
The importance of the dynamic structural evolution of water in the solid–liquid interface cannot be overstated. However, the ubiquitous hydrogen-bonded network is notoriously difficult to probe owing to complex interfacial environment. Formic acid , a fair hydrogen-bond donor and acceptor, is a promising reversible hydrogen storage/release material. Herein, isotope-labeled in-situ mass spectrometry (MS) and operando surface-enhanced Fourier transform infrared measurements ( operando FT-IR) reveal the central role of water during formic acid dehydrogenation . The water-promoted restructured HCOONa-Pd@ANI/C catalyst exhibits 100% selectivity, 100% conversion yield with high stability (even after 112 days) under ambient conditions. Coupled to a proton exchange membrane fuel cell, this integrated system reaches a high power density at 29.81 W⋅g Pd −1 . Our study demonstrates a new pathway involving water, the indispensable proton transfer and exchange through efficiently hydrogen-bonded network in light of operando experimental evidence.
研究领域:
催化化学
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材料科学
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表面化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2016
·
IF 4.012
Mazloom Shah,Fan Zhang,Ashfaq Ahmad
The catalytic conversion of substituted and unsubstituted cyclohexanones to the corresponding enones and aromatic alcohol catalyzed by Pd, Pd-1, Pd-cube, Cu, Ni, Ag@Pd and Ni-Sn nanocatalysts has been studied in the presence of O 2 as the oxidant without using any additives i.e. acid or base or ligand. The optimization of experimental parameters for dehydrogenation of cyclohexanones was established to achieve maximum yield of the product by using Pd nanocatalyst. The conversion of cyclohexanone, cyclohexenone, 3-methyl cyclohexanone and 3-methyl cyclohexenone catalyzed by Pd nanocatalyst at 80 °C, 10 atm O 2 pressure after 24 h, led to a 79%, 49%, 62% and 25% yields of desired products, respectively. Then, the conversion of substituted and unsubstituted cyclohexanones investigated in the presence of various nanocatalysts i.e., Pd-1, Pd-cube, Cu, Ni, Ag@Pd and Ni-Sn nanoparticles and was compared their percentage yields.
研究领域:
化学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
·
IF 7.139
Nan Lu,Xiaoqing Yan,Hui Ling Tan,Hisayoshi Kobayashi,Xuehan Yu,Yuezhou Li,Jiemei Zhang,Zhengxin Peng,Jing Sui,Ziying Zhang,Wen Liu,Renhong Li,Benxia Li
We report an efficient process to dehydrogenate formaldehyde in alkaline solution, catalyzed by carbon nanotubes (CNTs) via a unique reaction mechanism involving molecular O 2 . The superior catalytic performance of carbon nanotubes (CNTs) compared to the other carbon-based catalysts is attributed to their sp 2 -carbon-rich surface, hydrophilicity and abundant surface defects , which are the most plausible active sites. Peroxide species originating from the activation of adsorbed molecular oxygen on the CNTs is found to be a key to C–H activation, leading to efficient hydrogen production . The cost-effective carbon-based dehydrogenation catalysts offer new opportunities to the development of novel liquid organic hydrogen carrier technologies.
研究领域:
化学工程
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能源科学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2020
·
IF 4.939
Xiang Gong,Zhao Jiang,Tao Fang
N-ethylcarbazole/dodecahydro-N-ethylcarbazole (NECZ/12H-NECZ) was a promising system for hydrogen storage applications. 1.0 wt% Pt/TiO 2 was regarded as the optimal loading in Pt/TiO 2 catalyst applied in the 12H-NECZ dehydrogenation reaction. The hydrogen release amount, selectivity to NECZ and TOF of 12H-NECZ dehydrogenation are 5.75 wt %, 98% and 229.73 min −1 at 453 K. Compared with the commercial 5.0 wt% Pd and Pt-based catalysts, it exhibited very high activity, selectivity and stability for 12H-NECZ dehydrogenation with low Pt loading. Combined with the XRD , XPS , HRTEM , TPR analysis, it was indicated that the enhanced catalytic performance was due to the SMSI (strong metal-supporting interaction) between Pt and TiO 2 support, which accelerated the rate-limiting step and enhanced the whole dehydrogenation reaction. This work may be beneficial for the commercial application of Pt/TiO 2 catalysts in the Liquid Organic Hydrogen Carrier (LOHC) system.
研究领域:
化学工程
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材料科学
✓ 已验证
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
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2024
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IF 1.4
Bo Wang,Pei-ya Li,Shu-han Lu,Bin Wang,Fusheng Yang,Tao Fang
Liquid organic hydrogen carrier (LOHC) technology has unique advantages in hydrogen storage and transportation. However, the lack of research on the continuous dehydrogenation process of LOHCs has hindered the design and application of industrial dehydrogenation processes. In this work, a highly active dehydrogenation catalyst 1.5 wt% Pd/activated carbon (Pd/C) and a commercial catalyst 5 wt% Pd/Al 2 O 3 were used for the continuous dehydrogenation of dodecahydro-N-ethylcarbazole (12H-NEC). Based on a tubular reactor and lab-scale apparatus, 1.5 wt% Pd/C catalyst achieved a maximum dehydrogenation conversion of 98.3% and a maximum NEC selectivity of 95.3%, while dehydrogenation conversion and NEC selectivity with 5 wt% Pd/Al 2 O 3 were 98.3% and 97.6%, respectively. It showed the equally excellent performance between Pd/C and Pd/Al 2 O 3 , and the former has less Pd loading than the latter, with the potential of reducing the production cost of the dehydrogenation catalyst. The dehydrogenation results also indicated the difference in catalytic performance between the two kinds of catalysts. The obtained kinetics data were analyzed, and the dynamics of continuous dehydrogenation were studied to provide fundamental information for dehydrogenation scale-up.
研究领域:
化学工程
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
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
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2023
·
IF 6
Hong-Jun Lu,Dong-Hao Yuan,Chang Gao,Bi-Cheng Li,Zi-Bin Huang,Jing-Yi Yang,Pei-Qing Yuan
The effect of the timing of adding 1 wt% decalin as a hydrogen donor on heavy oil visbreaking was studied. Experiments show that either premixing decalin with heavy oil or adding decalin during the reaction accelerates the formation of light distillates and improves the efficiency of viscosity reduction. Premixing with heavy oil is an appropriate way to add decalin. After 10 min of reaction at 400 ℃, the viscosity reduction rate of the product reaches 90% and the asphaltene content of the product is 1.8 wt% lower than that of the raw heavy oil. According to theoretical calculations, the active hydrogens of decalin preferentially saturate the aromatic C radicals that are critical for condensation . The equilibrium constant of the H-donation reaches the order of 10 5 , while the activation energy of the reaction is only about 26 kJ/mol. The thermal cracking of decalin itself releases active and small-sized radicals, which accelerate visbreaking by participating in the dealkylation network of heavy oil molecules.
研究领域:
石油工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2025
·
IF 3.9
Jingrong Li,Tingting Xiao,Xinluona Su,Qihang Gong,Peikai Luo,Jian Li,Haiyang Cheng,Fengyu Zhao
Graphical The evolution of the geometric structure and electronic states of Pd species was revealed for Pd/C catalysts in catalyzing the dehydrogenation of 12H-NECZ. The oxidized Pd δ+ species was reduced to Pd 0 species with finely-dispersed on the surface of support to generate H 2 with a high efficiency of 98.3%. The dehydrogenation of liquid organic hydrogen carriers is of significant potential for hydrogen energy applications. We successfully synthesized a highly efficient and stable Pd/C catalyst featuring ultrasmall (2.22 nm) and stable Pd nanoparticles via the deposition–precipitation method for the dehydrogenation of dodecahydro- N -ethylcarbazole. Interestingly, the Pd structure evolves during the reaction, with the Pd 2+ species on Pd/C catalyst re-dispersing into uniformly small-sized Pd 0 nanoparticle under reaction conditions. The conventional thermal treatment of calcination–reduction typically results in larger Pd particles due to the stronger metal-support interaction. Kinetic studies revealed the oxidation state of Pd 2+ species (Pd(OH) 2 , PdO) is more active for the dehydrogenation reaction compared to the metallic state Pd 0 species. The in situ structure evolution induced ultrasmall Pd nanoparticles (2.22 nm) with a constant Pd 0 /Pd 2+ ratio, achieving a high efficiency (98.3%) of H 2 release from 12H-NECZ dehydrogenation at 180 °C. This work provides a simple method for preparing highly dispersed Pd/C catalyst with stable ultrasmall Pd particles, offering valuable insights to researchers in the field of supported metal catalysts.
研究领域:
催化化学
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材料科学
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能源化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
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IF 2.39
Pei Pei Yuan,Bin Hong Liu,He Peng Zhu,Wei Yuan Pan,Zhou Peng Li
In this work, the composites of LiBH 4 and AlF 3 were prepared and their hydrogen storage properties were investigated. The AlF 3 addition to LiBH 4 resulted in significant decreases in dehydrogenation temperature. All the x LiBH 4 + AlF 3 ( x = 1, 2, 3, 5) composites started to release hydrogen from about 100 °C. The dehydrogenation of the composites was accomplished through several steps, depending on the molar ratio of LiBH 4 to AlF 3 . A new phase Li 3 AlF 6 was formed during the first dehydrogenation step, which further reacted with LiBH 4 . AlB 2 was formed only at temperatures higher than 300 °C. Li 2 B 12 H 12 was detected as an intermediate. The dehydrogenation reactions have significantly reduced and thus favorable enthalpy changes. However, the reversibility of the composites needs to be improved.
研究领域:
材料科学
·
化学
✓ 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）