CATALYSIS LETTERS
·
2021
·Vol. 152
·期 5
·1372-1385
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IF 3.186
Qiu Baocheng,Zhang Yakun,Zhang Yi
The rapid deactivation caused by coke deposits is the major obstacle to the ethane aromatization of Zn-based catalysts. We have successfully synthesized a Zn-embedded inside HZSM-5 crystal catalyst (Zn@HZSM-5) by hydrothermal synthesis using preformed Zn/SiO 2 as the only silicone source. Based on various characterization results, including in situ etching XPS, operando DRIFTS, as well as NMR, it is found that Zn(OH) + and [Zn–O–Zn] 2+ species are active sites for ethane aromatization for zinc-based catalysts, and their dynamic transformation significantly changes reaction performance of ethane dehydrogenation. For the Zn/HZSM-5 catalyst, the existence of a large number of [Zn–O–Zn] 2+ species causes higher initial ethane conversion and higher selectivity of aromatics, resulting in a large amount of coke deposits. Moreover, [Zn–O–Zn] 2+ species on the Zn/HZSM-5 catalyst fast transit to Zn(OH) + species and subsequently form the sintered ZnO species, leading to rapid deactivation. For the Zn@HZSM-5 catalyst, the embedded structure contributes to forming more Zn(OH) + species and delays the transformation of the Zn(OH) + species to [Zn–O–Zn] 2+ species, resulting in slowly increased selectivity of aromatics during the reaction. Therefore, the Zn@HZSM-5 catalyst realizes stable ethane conversion with dynamic selectivity. Graphic Abstract
研究领域:
催化化学
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材料科学
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高影响因子
Foods
·
2022
·Vol. 11
·期 24
·4073
·
IF 5.561
Yingrui Ji,Dongming Lan,Weifei Wang,Kok Ming Goh,Chin Ping Tan,Yonghua Wang
With the prevalence of edible diacylglycerol (DAG) oil, which is beneficial to human, the generation of 3-monochloropropanediol esters (3-MCPDE) and glycidyl esters (GE) as well as the stability of physical properties during heat-induced processing still need to be explored. In this study, the experiment used olive-based edible oil with different contents of DAG (40, 60, and 80%) to make crackers and fry chicken. They were heated at 160 and 180 °C to determine the changes in 3-MCPDE and GE, the crackers’ hardness and gumminess, and the physical properties of the oil. During baking and frying, 3-MCPDE decreased, while the content of GE slightly increased with the prolonged heating duration. Finally, 3-MCPDE and GE were lower than 1.25 mg/kg and 1.00 mg/kg, respectively. The AV increased proportionally as duration increased and POV was below 0.30 g/100 g. In general, the changes in 3-MCPDE and GE were related to the heating temperature and duration, and not significantly (p> 0.05) related to the content of DAG.Keywords:3-MCPD ester;glycidyl ester;diacylglycerol;crackers;frying oil
研究领域:
食品科学
·
化学
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2022
·
IF 4.326
Mingshuai Sun,Fumin Wang,Guojun Lv,Xubin Zhang
Overhydrogenation to ethane is most undesired in selective hydrogenation of acetylene. Monometallic Pd supported on common oxide supports such as alumina and silica suffers from susceptibility of ethane formation, and the ethylene selectivity is usually unsatisfactory. Herein, Fe5C2 was carefully synthesized and employed as a new kind support doped with a (5–600) ppm level of Pd for selective hydrogenation of acetylene. The catalyst with appropriate Pd loadings exhibited more efficient ethane suppression and much higher ethylene selectivity than the traditional α-Al2O3 supported Pd catalyst, with full acetylene conversion under 240 °C, and maintained good stability after a 200 h tolerance test. Characterization and DFT calculation results reveal that the excellent ethylene selectivity is mainly derived from the special interaction between Pd atoms and the Fe5C2 support. Hydrogenation of ethylene to ethane needs to cross extremely high activation energy barriers on the catalyst surface, and ethylene desorption more easily occurs on it. Doping the appropriate amount of Pd atoms on the Fe5C2 surface can increase the obstacle for polymerization and will cause the unsaturated C2 species to be more inclined to be hydrogenated into C2H4. This synergy effect also acts as a guide in alkane suppression for selective hydrogenation of other alkynes.
研究领域:
化学工程
·
催化科学
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Shao-Min Wang,Hao-Ran Liu,Su-Tao Zheng,Hao-Ling Lan,Qing-Yuan Yang,Yan-Zhen Zheng
The purification of ethylene (C 2 H 4 ) by selective adsorption of small amounts of ethane (C 2 H 6 ) is a crucial industrial process. However, most porous adsorbents prefer C 2 H 4 over C 2 H 6 due to the increase in kinetic diameter and decrease in quadrupole moment from C 2 H 4 to C 2 H 6 . The construction of ethane-selective adsorbents for ethylene purification is therefore a very challenging task. In this study, we designed and synthesized a family of C 2 H 6 -selective metal–organic framework (MOF) adsorbents, named Co-1-ina , Co-5-ina and Co-9-ina , through the strategy of crystal engineering using the same metal salt (Co 2+ ) and ligand (isonicotinic acid). Notably, the pore structures and topologies of these materials vary according to the reaction conditions. Among them, Co-9-ina has the highest C 2 H 6 adsorption capacity and C 2 H 6 /C 2 H 4 separation performance. The C 2 H 6 /C 2 H 4 selectivity of Co-9-ina at 298 K and 1 bar is astoundingly 2.69, which is greater than most C 2 H 6 -selective MOFs reported to date. The pyridine rings bind more strongly to C 2 H 6 via van der Waals interactions for ethane adsorption according to theoretical calculations and single crystal structures. The C 2 H 6 /C 2 H 4 separation performance for Co-9-ina was further validated by breakthrough studies under dynamic conditions.
研究领域:
材料科学
·
化学工程
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Shi-Ming Li,Hong-Chan Jiang,Qing-Ling Ni,Liu-Cheng Gui,Xiu-Jian Wang
Ethane (C 2 H 6 ) and ethylene (C 2 H 4 ) have similar physical and chemical properties, which are critical and difficult for the separation of C 2 H 6 /C 2 H 4 mixtures in the petrochemical process. Traditional C 2 H 4 -selective adsorbents can separate the C 2 H 6 /C 2 H 4 mixtures, but need further desorption treatment to obtain pure C 2 H 4 production. On the contrary, high-pure C 2 H 4 can be prepared in one step by C 2 H 6 -selective porous material. Herein, we present a caged metal-organic framework ( GNU-2 ) based on Zn (II) clusters, which has advantageous adsorption sites and cavity pockets for the reverse capture of C 2 H 6 from C 2 H 6 /C 2 H 4 mixtures. At 298 K and 1 bar, high C 2 H 6 uptake (5.10 mmol g −1 ) and C 2 H 6 /C 2 H 4 selectivity (1.849) were attained based on the activated GNU-2 ( GNU-2a ), exceeding a number of top C 2 H 6 -selective adsorbents. Grand canonical Monte Carlo (GCMC) simulations exhibit that the appropriate chemical environment of nonpolar cage in GNU-2a allows it to continuously maintain closer van der Waals contacts between C 2 H 6 molecule, saturated Zn cluster and nonpolar pore surface through multiple C H···O hydrogen interactions and C H···π hydrogen interactions. Moreover, dynamic breakthrough studies also show that GNU-2a displays the actual separation performances of C 2 H 6 .
研究领域:
化学工程
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材料科学
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Ruolin Cheng,Anhu Wang,Shuxun Sang,Huagen Liang,Shiqi Liu,Panagiotis Tsiakaras
The CO 2 cycloaddition of epoxides is a highly attractive long-term carbon fixation strategy, but harsh reaction conditions and expensive catalytic materials limit its industrial application. Herein, low-cost and highly efficient W 18 O 49 -based composites were constructed by in-situ solvothermal synthesis. It is found that W 18 O 49 /g-C 3 N 4 composites exhibit the highest yield of 74% (271 mmol g −1 h −1 ) in the probing reaction of styrene carbonate production. The physicochemical characterizations indicate that the photocatalysis plays a fundamental role in this reaction by promoting the activation of CO 2 and styrene oxide. The crucial role of photogenerated electrons and Lewis acid-base sites is confirmed. In this work, a novel catalyst selection to produce cyclic carbonate under ambient conditions is presented.
研究领域:
材料科学
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环境科学
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化学工程
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高影响因子
Catalysts
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2019
·Vol. 9
·期 9
·726
·
IF 3.444
Jian Wang,Hainan Zhao,Jianfei Song,Tingyu Zhu,Wenqing Xu
Manganese oxide catalysts, including γ-MnO2, Mn2O3and Mn3O4, were synthesized by a precipitation method using different precipitants and calcination temperatures. The catalytic oxidations of benzene and 1,2-dichloroethane (1,2-DCE) were then carried out. The effects of the calcination temperature on the catalyst morphology and activity were investigated. It was found that the specific surface area and reducibility of the catalysts decreased with the increase in the calcination temperature, and both the γ-MnO2and Mn3O4were converted to Mn2O3. These catalysts showed good activity and selectivity for the benzene and 1,2-DCE oxidation. The γ-MnO2exhibited the highest activity, followed by the Mn2O3and Mn3O4. The high activity could be associated with the large specific surface area, abundant surface oxygen species and excellent low-temperature reducibility. Additionally, the catalysts were inevitably chlorinated during the 1,2-DCE oxidation, and a decrease in the catalytic activity was observed. It suggested that a higher reaction temperature could facilitate the removal of the chlorine species. However, the reduction of the catalytic reaction interface was irreversible.Keywords:benzene;1,2-Dichloroethane;catalytic oxidation;manganese oxide catalysts
研究领域:
环境科学
·
催化化学
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DOI
高影响因子
Journal of the American Chemical Society
·
2025
·
IF 15.6
Lei Luo,Rong Wang,Tieou Wang,Jiangnan Li,Yejun Xiao,Kun Qi,Xiangyang Guo,Zhaochi Feng,Junwang Tang,Fuxiang Zhang
Direct methane conversion to value-added chemicals under mild conditions presents a promising route toward net-zero carbon emissions. However, this process encounters significant challenges in efficiently activating inert C–H bonds and preventing excessive oxidation to CO2. Herein, we propose a coverage-dependent strategy that leverages the correlation between methane coverage and C–C coupling selectivity, thereby enhancing both the activity and selectivity. By tuning the Lewis acidity of a well-defined atomic 3d transition metal-modified ceria, from weak to moderate, it boosts methane adsorption capacity and promotes its dissociative activation. Additionally, incorporating a nickel cocatalyst improves the charge separation through efficient hole extraction. The optimal noble-metal-free catalyst (Ni1-CeO2) delivers exceptional room-temperature performance, achieving a production rate of 243 μmol·g–1·h–1 with approximately 90% ethane selectivity over an ultralong test (>350 h), outperforming previously reported noble-metal-free catalysts. This work provides new insights into selectivity regulation via optimization of chemisorbed methane coverage and paves the way for the design of advanced noble-metal-free catalysts.
研究领域:
化学工程
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催化科学
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PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Jinwei Qin,Peng Zhao,Jie Meng,Shixiang Zuo,Xiaohui Wang,Wei Zhu,Wenjie Liu,Jingwei Liu,Chao Yao
Higher specific surface area and abundant surface oxygen vacancies are considered to be essential to the catalytic combustion. Herein, we elaborately fabricated an innovative catalyst on the basis of LaMnO 3 @Co 2 MnO 4 under a controllable selective dissolution (SD) treatment for ethane catalytic combustion. La element in perovskite could effectively protect the spinel system as a sacrifice, with MnO 2 covering on the spinel surface, thereby enhancing the activity and stability. In combination with XPS, in-situ DRIFT and various characterization results, this acid corrosion could provide induce better reducibility, larger specific surface area, higher Mn 4+ and Co 3+ content and more oxygen vacancies , which played a significant role in promoting the adsorption, activation and decomposition of ethane. Among all as-prepared catalysts, the optimal performance for catalytic ethane combustion was achieved on LMO@CMO-10 catalyst. The T 90 of LMO@CMO-10 was 341 °C under space velocity of 80,000 mL·g −1 ·h −1 . This work not only fabricated the catalyst system with higher specific surface area and more oxygen vacancy by SD method, but also provided a potential strategy for the preparation of highly active catalysts.
研究领域:
材料科学
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催化化学
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高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Jing Wang,Sisi Fan,Hongmin Duan,Jinming Xu,Yanqiang Huang
Carbon spheres with hierarchical pore structure were successfully synthesized by using strongly basic anion exchange resins exchanged with silicate, followed by pyrolysis in an inert atmosphere and etching silica. As a result of the quaternary ammonium group in the anion exchange resin structure, these carbon spheres were doped with nitrogen. The performance of these carbon spheres in the catalytic dehydrochlorination of 1,2-dichloroethane (EDC) was improved with the increase of calcination temperature, and the carbon sphere 900-900-RC showed the highest conversion rate (96.7%) and a selectivity to vinyl chloride above 99%. The structural and surface properties of N-doped carbon spheres were characterized by scanning electron microscopy, nitrogen sorption, and Raman and X-ray photoelectron spectroscopy. The result of these characterizations further verified that the quaternary nitrogen species are as effective as pyridine nitrogen species in this catalyst.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF CATALYSIS
·
2022
·
IF 8.047
Yuxin Chen,Shuairen Qian,Kai Feng,Zhengwen Li,Binhang Yan,Yi Cheng
The original phase-pure M1 MoVNbTeO x catalyst was mechanically treated with stirring water for several days under ambient conditions to obtain particles with different sizes. The catalytic performance was significantly improved and stabilized after about 7 days of treatment. Among all the catalysts, the sample treated in water for 7 days can obtain 57.6 % ethane conversion and 0.79 kg C2H4 /kg cat /h ethylene productivity while the original phase-pure M1 catalyst was only 19.2 % and 0.27 kg C2H4 /kg cat /h at reaction temperature of 400 °C and contact time of 18.5 g cat ·h/mol C2H6 . Meanwhile, the catalyst was systematically characterized and the results showed that there was essentially no difference in microstructure between the original and treated catalysts. TEM and SEM morphological characterizations presented that the particle size and aspect ratio of the catalysts changed significantly, in which the particle size of the catalyst become smaller and the proportion of basal surface was enhanced. The activity and selectivity of the catalysts exhibited a correlation with the amount and proportion of basal surface. It can be deducted that the basal surface is the most active and selective surface during oxidative dehydrogenation of ethane (ODHE) process, and the intrinsic activity based on the basal (0 0 1) plane of the catalyst remains stable after the mechanical treatment. Samples treated in water for 7 days showed excellent long-term stability in a 200 h stability test at reaction temperature of 440 °C and contact time of 9.3 g cat ·h/mol C2H6 . The present work demonstrated that the differences in the catalytic properties of different M1 samples depend mainly on the amount and proportion of exposed basal surface, and the possibility of enhancing the activity of orthorhombic M1 phase by fragmentation method.
研究领域:
催化化学
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材料科学
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高影响因子
CHEMISTRY OF NATURAL COMPOUNDS
·
2019
·Vol. 55
·期 1
·172-174
·
IF 0.567
Zhang H.,Wu J.,Zhu F.,Zhang X.,Zhu X.
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材料科学
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