PLASMA CHEMISTRY AND PLASMA PROCESSING
·
2024
·
IF 2.6
Gang Yonggang,Long Yanhui,Wang Kaiyi,Zhang Yilin,Ren Xuping,Zhang Hao,Li Xiaodong
Recently, direct non-oxidative conversion of methane (NOCM) into hydrogen and light hydrocarbons has garnered considerable attention. In our work, we employed a dielectric barrier discharge (DBD) plasma over a GaN/SBA15 catalyst for NOCM. Adding catalyst to plasma remarkably promotes the conversion of CH 4 , resulting in a significant improvement, for instance, from 27.8 to 39.2%. A systematic investigation of plasma performance at different discharge powers with and without catalyst was conducted. In the case of plasma + 15wt% GaN/SBA15, CH 4 conversion reaches an impressive 79.4%. However, it exhibits the lowest selectivity of 14.4% for C 2 +, while achieving the highest selectivity for hydrogen at 48.9%. Several characterization methods, including XRD, SEM, BET, XPS, and TPO-MS, were used to study the mechanism of the reaction. Plasma electrons and ions can effectively interact with activated CH3 radicals, promoting their adsorption onto Ga sites on the catalyst surface. Simultaneously, hydrogen atoms adsorb onto neighboring N atoms, rapidly delocalizing to produce H 2 , and the delocalization of hydrogen atoms in C species leads to the formation of species like CxHy. This study highlights the potential of plasma catalysis in significantly improving CH 4 conversion at lower temperatures and atmospheric pressure.
研究领域:
化学工程
·
能源科学
·
催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Xin Kang,Jiancong Liu,Dongxu Wang,Chungui Tian,Honggang Fu
CO 2 hydrogenation to hydrocarbons under high space velocity is crucial for industrial applications, but traditional Fe-based catalysts often suffer from the low activity and poor stability. Herein, we report a new tandem catalyst system combining Pt/TiO 2 catalysts with Fe 3 C catalysts for the direct conversion of CO 2 into C 2 -C 4 hydrocarbons under high space velocity. The Pt/TiO 2 component promotes *CO intermediate production with an enhanced Reverse Water-Gas Shift (RWGS) reaction efficiency, providing a highly reactive species for the Fe 3 C catalyst to achieve Fischer-Tropsch synthesis (FTS). By maximizing the contact interface between the Pt/TiO 2 and Fe-based components through a granule mixing configuration, we achieve significant enhancements in both CO 2 conversion rate (24.0 %) and C 2 -C 4 hydrocarbons selectivity (51.1 %) under the gaseous hourly space velocity (GHSV) of 100000 mL g cat −1 h −1 . Besides, excellent stability is achieved by the tandem catalysts with continuous catalysis for up to 80 h without significant decrease in activity. Through modulation of the reduction states of iron oxide, we effectively tune the composition of Fe-based catalyst, thereby tailoring the product distribution. Through this work, we not only offer a promising avenue for reducing CO 2 for efficient CO 2 utilization but also highlight the importance of catalyst design in advancing sustainable chemical synthesis.
研究领域:
催化化学
·
环境科学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Fanhui Meng,Lina Wang,Muhammad Asif Nawaz,Qian Wang,Zhiyuan Gong,Zhong Li
Direct conversion of syngas to light hydrocarbons has been intensively studied in recent years; however, the high selectivity of light hydrocarbons is still a challenging task to achieve a high CO conversion. Here, a bifunctional catalyst consisting of a methanol synthesis catalyst (CZA) and a methanol to dimethyl ether (DME) catalyst (Al 2 O 3 ) was employed with a hydrocarbon synthesis catalyst (SAPO-34), for syngas conversion to light hydrocarbons in a dual fixed-bed reactor. The conversion of simulated intermediates CO/CO 2 /DME/N 2 /H 2 with a molar ratio of 9/6/4/5/76, obtained from syngas conversion to DME over CZA and Al 2 O 3 , was studied over SAPO-34 zeolites. It was found that SP34-0.1 with Si/Al ratio of 0.1, exhibited low amount of strong acid (0.60 mmol/g) and high selectivity to light olefins (74.1%), while SP34-0.4 with Si/Al ratio of 0.4 exhibited high amount of strong acid (1.00 mmol/g) leading to high selectivity of light paraffins (88.4%). The in-situ DRIFTS analysis illustrated that DME can be rapidly adsorbed on the hydroxyl site of SAPO-34 and decomposed into the surface methyl species, where SP34-0.4 could produce more dimethylcyclopentenyl cationic species than SP34-0.1. It was suggested that the overall reaction route led to a high selectivity to light olefins (84.2%) with a CO conversion of 61.2% on (CZA + Al 2 O 3 ) catalyst combined with SP34-0.1, while a high selectivity to light paraffins (76.3%) could be achieved by combining with SP34-0.4 at 70.3% CO conversion. Since, the current study interprets that the selectivity of hydrocarbons can be adjusted by regulating the acidity of SAPO-34 to achieve a high CO conversion in the dual fixed-bed reactor scheme.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
ORGANIC GEOCHEMISTRY
·
2024
·
IF 2.6
Wenna Liu,Wanglu Jia,Qiang Wang,Jian Chen,Jinbu Li,Ping’an Peng
The isotopic fractionation of organic compounds during evaporation is one of the most critical issues in the field of stable isotopes. The hydrogen (H) isotopic compositions of light hydrocarbons (LHs) in oil have gained increasing interest in the research of oil genesis in recent years. However, compared to carbon (C) isotopes, our understanding of H isotopic fractionation patterns and influences for various types of LHs during evaporation is limited. In this study, we performed evaporation experiments at a constant temperature on LHs in three systems: single compound, alkane mixture, and light oil. We assessed the contents and H isotopic compositions of individual LHs in the residual liquid phase. The degree of H isotopic fractionation and influencing factors are studied combined with C isotopes. The H isotopic fractionation of LHs exhibits “inverse isotope fractionation” characteristics (a depletion in D in the residual LHs) with progressive evaporation, which is opposite to the C isotopic fractionation. The degree of isotopic fractionation is influenced by the evaporation system, the compounds’ molecular weight, and their structure. (1) The isotopic fractionation degree of H and C decreases in the following order: light oil > alkane mixture > single compound system. This difference may be related to the unsaturation level of the evaporative system and the evaporation matrix. (2) For LHs with the similar structure in the same evaporation system, the degree of H isotopic fractionation increases with increasing molecular weight due to the buffering effect of the sample pool, while the magnitude of C isotopic fractionation decreases. (3) For LHs with the same C number, methylcyclohexane (MCH) has a lower evaporation rate and less isotopic fractionation than the other C 7 compounds like 3-methylhexane (3-MH), n -heptane ( n C 7 ), and toluene (Tol). The distinctive fractionation characteristics of H isotopes make them very useful in geological applications. Combining H and C isotopic compositions of the same compound with the commonly used molecular ratios of LHs (e.g., n C 7 /MCH, Tol/ n C 7 ) enables full differentiation of three critical processes controlling oil formation: evaporation, thermal maturation, and biodegradation. Furthermore, the differences in H isotopic compositions between C 7 LHs (3-MH, n C 7 , and Tol) may be changed by evaporation, but the variation range is much smaller than that caused by source differences. Therefore, combining H and C isotopes may have great potential for oil source characterizations.
研究领域:
地球化学
·
石油地质学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Yuning Tang,Sa Wang,Xin Zhou,Ying Wu,Shikai Xian,Zhong Li
A facile and efficient room-temperature synthesis approach was proposed to prepare MOF material Cu(Qc) 2 (henceforth called RT-Cu(Qc) 2 ) with ultramicropores. RT-Cu(Qc) 2 was successfully synthesized at room-temperature by means of (Zn, Cu) hydroxyl double salt as intermediate within 1–12 h. The resulting RT-Cu(Qc) 2 exhibited excellent water vapor stability and its C 2 H 6 uptake reached 2.19 mmol/g at 288 K and 1 bar. Its C 2 H 6 /C 2 H 4 and C 2 H 6 /CH 4 uptake ratio at 298 K and 1 bar were up to 3.70 and 22.67, superior to benchmark MAF-49, Cu(Qc) 2 and ZIF-7. Its IAST-predicted C 2 H 6 /C 2 H 4 and C 2 H 6 /CH 4 selectivity reached 4.1 (1:1 v:v) and 35.9 (1:9 v:v) at 288 K and 1 bar, higher than most of ethane-capturing MOFs. Molecular simulation revealed well-defined host–guest match between Cu(Qc) 2 and ethane. Fixed bed experiments confirmed that ethane/ethylene or ethane/methane mixtures can be completely separated using RT-Cu(Qc) 2 . RT-Cu(Qc) 2 has great potential for separation of ethane/ethylene and the recovery of ethane from natural gas.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Yufang Wu,Yiwei Sun,Jing Xiao,Xun Wang,Zhong Li
In this work, a novel Gly@HKUST-1 with simultaneously enhanced moisture stability and improved adsorption capacity was developed by grafting glycine (Gly) onto the open metal sites of HKUST-1, in order to recover light hydrocarbons from natural gas efficiently. The resultant Gly@HKUST-1 had higher C2H6 and C3H8 adsorption capacities compared to HKUST-1 and some other metal–organic frameworks, which reached as high as 6.47 and 7.80 mmol/g at ambient conditions. Its C2H6/CH4 and C3H8/CH4 adsorption selectivities were up to 12.6 and 173.5, respectively. Fixed-bed experiments showed that 0.3Gly@HKUST-1 could separate the CH4/C2H6/C3H8 mixtures completely at ambient conditions, showing excellent separation property toward the light hydrocarbons. More importantly, stability experiments confirmed that after the two samples were exposed to moist air (RH of 55%) for 20 days, 0.3Gly@HKUST-1 still remained its crystal structure, while parent HKUST-1 lost most of its crystallinity. Computational simulations showed that Gly grafting onto unsaturated Cu site played a critical role in enhancing stability against water vapor and improving capacity due to its shielding of unsaturated Cu site as well as introduction of −COOH or −NH2 as the H-binding sites. Gly@HKUST-1 is promising for practical application of efficiently recovering ethane and propane from natural gas by adsorption.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 18
·9989-9999
·
IF 11.9
Guang-Xing Dong,Meng-Ran Zhang,Ke Su,Zhao-Lei Liu,Min Zhang,Tong-Bu Lu
Activation and catalytic transformation of C–H bonds under mild conditions has long been a great challenge for the chemical industry. Herein, we report a halide-perovskite-based photocatalyst composed of manganese-doped CsPbBr3 decorated on BiVO4 for the efficient and selective transformation of nonpolar CH4 to oxygenates using air as an oxidant. At room temperature and atmospheric pressure, the yield and selectivity of oxygen-containing hydrocarbons (CH3OH and HCHO) from photocatalytic CH4 oxidation are as high as 533.5 μmol g−1 h−1 and 94.8%, respectively. Moreover, transient intermediate capture and isotope labeling experiments demonstrate that the oxygen sources of products for this heterojunction are mainly from O2, which contrasts with that from water in pristine BiVO4, owing to the difference in the pathway of O2 reduction induced by the increased thermodynamic driving force. This work provides an effective strategy for the design and development of a cost-effective catalyst system for CH4 conversion in a mild manner.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYHEDRON
·
2024
·
IF 2.4
Meng Zhao,Yun Yang,Xue-Song Gu,Lanlan Sun
The separation and purification of light hydrocarbons are performed by energy-intensive distillation processes. Microporous metal–organic framework based absorbents acting as alternative technology gains focus. Open metals sites (OMSs) enriched MOF-74 show great potential in light hydrocarbons but its separation selectivity is low and difficult to regenerate. To address this issue, we introduced N -donor ligands into open sites of Co-MOF-74 by post modification. Structure was determined by powder X-ray diffraction, element analysis, infrared spectroscopy and thermogravimetric analyses. As-synthesized modified Co-MOF-74 display potential in C 2 H 4 /C 2 H 6 , C 3 H 6 /C 3 H 8 , C 3 H 8 /CH 4 and C 2 H 6 /CH 4 separation for N -donor ligands placeholder.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Peixin Zhang,Xin Wen,Liang Wang,Yao Zhong,Yun Su,Yan Zhang,Jun Wang,Jiangfeng Yang,Zheling Zeng,Shuguang Deng
Light hydrocarbons are important alternative energy sources and raw materials, thus developing efficient adsorbents is of great importance for separating each C1/C2/C3 component in a pressure swing adsorption (PSA) process. Herein, we selected low-cost and ultrafast-growing algae as the precursor and applied the facile one-pot method to prepare N-doped porous carbons. The obtained algae-derived N-doped porous carbons (ANPCs) showed ultrahigh specific surfaces areas of 1437–3177 m 2 g −1 , large pore volumes of 0.637–2.18 cm 3 g −1 , and rich N-heteroatom content of 1.74–10.37 wt%. Moreover, the ANPC samples exhibited outstanding C 3 H 8 (11.5 mmol g −1 ), C 3 H 6 (11.3 mmol g −1 ), C 2 H 6 (6.84 mmol g −1 ), and C 2 H 4 (5.71 mmol g −1 ) adsorption capacities with excellent IAST separation selectivities of C3/C1 (189), C2/C1 (15.3), and C3/C2 (9.81) at 298 K and 1.0 bar. Impressively, ANPC-1-800 showed the C 2 H 6 -selective adsorption feature that is much more favorable in C 2 H 4 /C 2 H 6 separation. Furthermore, the detailed evaluation of VSA working parameters, dynamic breakthrough experiment, and adsorption cycle experiment confirmed that the ANPCs are potent and promising adsorbents for practical light hydrocarbon separation.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2020
·Vol. 61
·期 3
·662-668
·
IF 1.917
Jinghu Chen,Lingchang Jiang,Chengyun Li,Wenying Fu,Qineng Xia,Yangang Wang,Yuandong Huang
Light hydrocarbon separation is a crucial process associated with high energy expenditure in the petrochemical industry. The utilization of porous organic materials as solid porous adsorbents for light hydrocarbon separation has found widespread attention because of the advantages of low cost, excellent stability, and good recyclability. Here, we present the facile synthesis of a porous organic material, constructed from pyridine-triphenylborane by using a Friedel-Crafts alkylation coupling reaction, affording the hyper-cross-linked polymer, HCP-B. HCP-B features significant thermal stability, and high surface area. Gas adsorption experiments show that this material adsorbs much larger amounts of ethane, ethylene, and acetylene than that of methane. Ideal adsorbed solution theory (IAST) calculations also predict that HCP-B selectively adsorbs ethane, ethylene, and acetylene over methane. Both are indicative of the great potential of HCP-B in light hydrocarbon separation.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Lingyao Wang,Wanqi Sun,Simon Duttwyler,Yuanbin Zhang
A closo -dodecaborate [B 12 H 12 ] 2- functionalized metal organic framework (MOF), BSF-3, constructed by the self-assembly of the Cu(II) cation, 1,4-di(pyridin-4-yl)benzene linker and cluster [B 12 H 12 ] 2- pillar was investigated for the adsorption separation of light hydrocarbons. The activated MOF exhibited efficient uptake of CO 2 and C2–C3 hydrocarbons with high separation selectivity of C 3 H 8 (138), C 2 H 2 (205), C 2 H 4 (23), C 2 H 6 (13) and CO 2 (9) over CH 4 , outperforming many popular MOFs. The practical gas separation ability for C 2 H 2 /CH 4 , CO 2 /CH 4 and C 3 H 8 /C 2 H 6 /CH 4 was confirmed by mixed gas breakthrough experiments with no capacity loss after 7 cycles, indicating its potential for purification of methane from natural gas and pyrolysis gas. The gas bonding sites within the framework were further studied by modelling studies, which indicated that the anionic [B 12 H 12 ] 2- pillar contributed the most to capturing hydrocarbon molecules by multiple B-H δ- ···H δ+ -C interactions.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2018
·
IF 6.578
Daowei Zhou,Yixing Zhong,Jie Yang,Jiangyu Qi,Yayun Zhuo,Yong Sha
By means of chemical combination between the Polydimethylsiloxane (PDMS) layer and Polyethersulfone (PES) layer, a kind of PDMS/PES composite membrane was prepared for separation of the light hydrocarbon components from the drilling mud. Meanwhile, its separation performance of the light-hydrocarbon components from the drilling mud was investigated and evaluated quantitatively. Results showed that the prepared PDMS/PES composite membrane had good mechanical performance, and it was resistant to corrosion of the water-based drilling mud. The PDMS/PES composite membrane can work stably at 5 MPa and 393 K. The responding time of the membrane to sudden change of the hydrocarbon gas content was less than one minute. For either single phase flow or gas-liquid two-phase flow, a high flow rate was recommended to avoid non-ideal flow patterns and to increase mass transfer in the feed channel of the membrane cell . Results in this work could be helpful for further application of the membrane technology in geological mud logging.
研究领域:
材料科学
·
石油工程
✓ 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）