DALTON TRANSACTIONS
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2024
·Vol. 53
·期 7
·2957-2963
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IF 3.5
Peng Zhang,Sai Ma,Yujuan Zhang,Chaohui He,Tuoping Hu
The energy-saving separation of CO2/N2 and CH4/N2 in the energy industry facilitates the reduction of greenhouse gas emissions and replenishes energy resources, but is a challenging separation process. The trade-off between adsorption capacity and selectivity of the adsorbents is one of the key bottlenecks in adsorption separation technologies’ large-scale application in the above separation task. Herein, we introduced a series of fluoroborate or fluorosilicate salts (Cu(BF4)2, Zn(BF4)2 and ZnSiF6) into the open coordination nitrogen sites of aluminum-based metal–organic frameworks (MOF-253) to create multiple binding sites to simultaneously enhance the adsorption capacity and selectivity for the target gas. By the synergistic adsorption effect of metal ions (Cu2+ or Zn2+) and fluorinated anions (BF4− or (SiF6)2−), the single-component adsorption capacity and selectivity of salt-modified MOF-253 (MOF-253@Cu(BF4)2, MOF-253@Zn(BF4)2 and MOF-253@ZnSiF6) for CO2 and CH4 were effectively improved when compared to pristine MOF-253 at 298 K and 1 bar. In addition, the salt-modified MOF-253 has a moderate adsorption heat (<30 kJ mol−1) which could be rapidly regenerated at low energy by evacuation desorption. As confirmed by the ambient breakthrough experiments of MOF-253 and MOF-253@ZnSiF6, the real separation performance for both CO2/N2 (1/4) and CH4/N2 (1/4) was obviously improved. This work provides a feasible post-modification strategy on uncoordinated sites of the framework to improve adsorption separation performance and promote the development of ideal adsorbents with a view to realizing their application in the energy industry.
研究领域:
化学工程
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材料科学
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环境科学
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能源工业
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DOI
PubMed
高影响因子
Nature Communications
·
2019
·Vol. 10
·期 1
·1-12
·
IF 11.878
Cao Na,Chen Zheng,Zang Ketao,Xu Jie,Zhong Jun,Luo Jun,Xu Xin,Zheng Gengfeng
The electrochemical N 2 fixation to produce ammonia is attractive but significantly challenging with low yield and poor selectivity. Herein, we first used density function theory calculations to reveal adjacent bi-Ti 3+ pairs formed on anatase TiO 2 as the most active electrocatalytic centers for efficient N 2 lying-down chemisorption and activation. Then, by doping of anatase TiO 2 with Zr 4+ that has similar d -electron configuration and oxide structure but relatively larger ionic size, the adjacent bi-Ti 3+ sites were induced and enriched via a strained effect, which in turn enhanced the formation of oxygen vacancies. The Zr 4+ -doped anatase TiO 2 exhibited excellent electrocatalytic N 2 fixation performances, with an ammonia production rate (8.90 µg·h −1 ·cm −2 ) and a Faradaic efficiency of 17.3% at −0.45 V versus reversible hydrogen electrode under ambient aqueous conditions. Moreover, our work suggests a viewpoint to understand and apply the same-valance dopants in heterogeneous catalysis, which is generally useful but still poorly understood.
研究领域:
材料科学
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电化学
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2020
·
IF 7.632
Jiangzhou Qin,Baojun Liu,Kwok-Ho Lam,Shijie Song,Xinyong Li,Xia Hu
To improve the photocatalytic efficiency of the N2 reduction reaction, MXene quantum dots (Ti3C2-QDs) and two-dimensional (2D) nickel metal–organic framework (Ni-MOF) with different ratios were fabricated by a simple self-assembly strategy to form type II heterojunctions. The resultant composites showed enhanced absorption and excellent interfacial charge-transfer capabilities according to the optical and photoelectron properties. The optimal Ti3C2-QD/Ni-MOF heterostructure exhibited a considerable ammonia yield rate (88.79 μmol gcat–1 h–1). By means of X-ray absorption near-edge fine structure (XANES) technique, it was found that the interaction of Ti3C2-QD and Ni-MOF could accelerate the electron transfer, and Ni site would be the main area to enrich the electron density as well as adsorb and activate N2. Finally, with the aid of density functional theory (DFT) calculations and in situ Fourier transform infrared spectrometry (FTIR), the reaction pathway and intermediate products were studied.
研究领域:
材料科学
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环境科学
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化学
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DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 24
·8013
·
IF 4.6
Yuzhou Xia,Xinghe Xia,Shuying Zhu,Ruowen Liang,Guiyang Yan,Feng Chen,Xuxu Wang
Visible-light-driven N2reduction into NH3in pure H2O provides an energy-saving alternative to the Haber–Bosch process for ammonia synthesizing. However, the thermodynamic stability of N≡N and low water solubility of N2remain the key bottlenecks. Here, we propose a solution by developing a WO3−xhollow sphere with oxygen vacancies. Experimental analysis reveals that the hollow sphere structure greatly promotes the enrichment of N2molecules in the inner cavity and facilitates the chemisorption of N2onto WO3−x-HS. The outer layer’s thin shell facilitates the photogenerated charge transfer and the full exposure of O vacancies as active sites. O vacancies exposed on the surface accelerate the activation of N≡N triple bonds. As such, the optimized catalyst shows a NH3generation rate of 140.08 μmol g−1h−1, which is 7.94 times higher than the counterpart WO3-bulk.Keywords:WO3;hollow sphere;O defect;N2reduction;photocatalysis
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2018
·
IF 6.578
Xiong-Fei Zhang,Yi Feng,Zhongguo Wang,Mingmin Jia,Jianfeng Yao
Incorporating metal-organic frameworks into cellulose matrix to prepare composite membranes is promising in gas-separation applications. In this study, UiO-66-NH 2 (Zr-based MOF) nanoparticles are wrapped into the densely packed cellulose nanofibrils (CNF-COOH) via a facile vacuum filtration process. The existence of acid-base interactions and electrostatic forces between UiO-66-NH 2 and CNF-COOH renders ideal interfacial morphology. Results show that UiO-66-NH 2 is cross-linked by -COOH groups and well-dispersed in the CNF matrix. The porous UiO-66-NH 2 strengthens the diffusion process of CO 2 molecules, thus elevating the permeation flux and separation factor simultaneously. The optimum separation performance is achieved over CM-1 membrane with a CO 2 permeability of 139 Barrer and a CO 2 /N 2 selectivity ratio of 46.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
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2021
·
IF 5.909
Liwei Sun,Meilin Yin,Shaokun Tang
In this work, short-chain bi-functionalized ionic liquid (IL) was grafted onto mesoporous alumina (MA) for ideal CO 2 /N 2 selectivity . First, bi-functionalized IL 1-(2-carboxymethyl)-3-methoxyethyl-imidazolium bromide ([CmMOEim][Br]) with ether and carboxyl group was successfully synthesized and the initial decomposition temperature is 165 °C. Then low-cost hydroxyl-MA (MA-OH) was obtained from ordered MA (OMA) with the assist of 30 wt% H 2 O 2 solution to prepare [CmMOEim][Br]-grafted MA with different molar ratios of [CmMOEim][Br] and MA-OH via facile chemical reaction without the introduction of alkoxysilanes . MA-OH material presents slit-like structure and more hydroxyl groups compared to OMA sample before hydroxylation. Crystal structure and morphology of grafted material remains unchanged after grafting process. [CmMOEim][Br] is successfully grafted onto MA-OH via the chemical link of carboxyl group on IL and hydroxyl group on MA-OH. Finally, CO 2 and N 2 capture capacities of different materials were separately evaluated at 0.1 MPa and 25 °C. With the increase of IL dosage, CO 2 capture capacity of the grafting material first enhances and then decreases while N 2 capture capacity gradually falls owing to the high CO 2 affinity of [CmMOEim][Br]. Wherein, [CmMOEim][Br]-grafted MA-0.15 exhibits the optimum CO 2 capture capacity of 45.3 cm 3 /g at 25 °C and ambient pressure. The ideal CO 2 /N 2 selectivity of [CmMOEim][Br]-grafted MA can reach up to 30 based on single-component adsorption isotherms , which is higher than that of [CmMOEim][Br] and MA-OH. Furthermore, CO 2 capture capacity, morphology and structure of [CmMOEim][Br]-grafted MA maintain well even after ten cycles.
研究领域:
材料科学
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化学工程
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环境科学
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DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
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2024
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IF 4.4
Wei Li,Jingyun Wang,Mengmeng Han,Shanshan Xu
Obtaining pure clean energy methane (CH 4 , 3.80 Å) from natural gas is a great challenge task at present due to the similar kinetic diameter with nitrogen (N 2 , 3.64 Å). Herein, a well-defined rod-like bimetallic MOF (Cu 0.5 Ca 0.5 -SBMOF) with an excellent adsorption performance for CH 4 was successfully prepared and blended as filler with Matrimid® 5218 (PI) for preparing mixed matrix membranes (Cu 0.5 Ca 0.5 -SBMOF@PI MMMs). In the separation experiment of N 2 /CH 4 binary gas mixture, both filler loadings and trans -membrane pressure have significant effects on the separation performance of MMMs. When the filler loading is 20 wt%, Cu 0.5 Ca 0.5 -SBMOF@PI MMMs exhibits an excellent separation performance with a separation factor of CH 4 /N 2 up to 17.03, and the permeability of 22.57 barrer for N 2 , which significantly preceded the most reported MMMs. Moreover, the prepared MMMs also show excellent stability. This work has taken an important step towards practical application in the field of separating N 2 /CH 4 gas mixture using MMMs method.
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
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2025
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IF 3.7
Zhiwei Zhao,Yating Wang,Yuhao Tang,Xiaoqing Wang,Feifei Zhang,Jiangfeng Yang
Unconventional natural gas has become an important supplement to conventional energy sources, and the process of enrichment and purification of methane from low concentration coalbed methane is crucial. To this end, we report a copper-based metal–organic framework (MOF), ZJNU-119Cu, featuring two methane traps constructed with uncoordinated carboxylic acid oxygens and open metal sites. ZJNU-119Cu exhibits a high methane adsorption capacity (58.2 cm 3 ·g –1 ) at 298 K and 0.1 MPa and excellent CH 4 /N 2 separation performance under dynamic conditions. Density-functional theory calculations combined with grand canonical Monte Carlo simulation theory reveal the interaction mechanism for the uncoordinated carboxylic acid oxygen atoms and open metal sites in ZJNU-119Cu with CH 4 . The gas adsorption isotherms, heat of adsorption calculations, and breakthrough separation experiments indicate that this MOF is a very promising adsorbent for CH 4 /N 2 separation.
研究领域:
材料科学
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能源化学
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理论计算
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DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
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2020
·Vol. 26
·期 35
·7918-7922
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IF 4.857
Yichen Zhou,Mingmin Jia,Xiongfei Zhang,Jianfeng Yao
Graphical Filling the voids : Etched ZIF-8 (ZIF-8-E) crystals permeated by open through pores of size about 100 nm have been introduced into a polyethersulfone membrane matrix. The resulting material shows enhanced CO 2 /N 2 separation performance (see scheme). Zeolite ZIF-8 has been etched with acid to form microporous ZIF-8-E crystals. These were then introduced into a polyethersulfone (PES) membrane matrix to enhance its CO 2 /N 2 separation performance. Open through pores of size about 100 nm formed in the ZIF-8 crystals allow the ingrowth of polyethersulfone chains, ensuring a reduction in the number of nonselective voids, thereby achieving better interaction between ZIF-8-E and PES. As a result, the CO 2 /N 2 separation performance of the ZIF-8-E/PES membrane increased significantly, showing a CO 2 permeability of 15.7 Barrer and a CO 2 /N 2 ideal selectivity of 6.5.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
Biomass Conversion and Biorefinery
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2024
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IF 3.5
Jiang Ruiting,Yang Guang
The cost-effectiveness and renewability of biomass-derived carbon spheres have important advantages for wide application, yet efficient synthesis methods and green activation studies are still challenging. Here, hemicellulose from corncobs was extracted, and then N 2 plasma technology was used to modify the carbon spheres produced from hemicellulose in a single process. The effect of hydrothermal reaction parameters on the yield of carbon spheres was investigated, and the optimal preparation conditions were determined with solid–liquid ratio of 1:10 (g/mL), reaction time of 12 h, and pH of 1.5. The modified carbon spheres featured 3.02% nitrogen content and mesoporous structure. As an anode material for a lithium-ion battery, the modified sample has a specific capacity of 232.1 mAh g −1 after 50 cycles at 0.1 A g −1 . In this study, biomass-derived carbon spheres containing multifunctional groups were prepared under green and mild conditions, and this innovative process provides an effective basis for the sustainable utilization of biomass.
研究领域:
材料科学
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能源科学
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环境科学
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产品关联
DOI
高影响因子
Membranes
·
2021
·Vol. 11
·期 9
·693
·
IF 4.106
Fei Guo,Bingzhang Li,Rui Ding,Dongsheng Li,Xiaobin Jiang,Gaohong He,Wu Xiao
Mixing a polymer matrix and nanofiller to prepare a mixed matrix membrane (MMM) is an effective method for enhancing gas separation performance. In this work, a unique UiO-66-decorated halloysite nanotubes composite material (UiO-66@HNT) was successfully synthesized via a solvothermal method and dispersed into the Pebax-1657 matrix to prepare MMMs for CO2/N2separation. A remarkable characteristic of this MMM was that the HNT lumen provided the highway for CO2diffusion due to the unique affinity of UiO-66 for CO2. Simultaneously, the close connection of the UiO-66 layer on the external surface of HNTs created relatively continuous pathways for gas permeation. A suite of microscopy, diffraction, and thermal techniques was used to characterize the morphology and structure of UiO-66@HNT and the membranes. As expected, the embedding UiO-66@HNT composite materials significantly improved the separation performances of the membranes. Impressively, the as-obtained membrane acquired a high CO2permeability of 119.08 Barrer and CO2/N2selectivity of 76.26. Additionally, the presence of UiO-66@HNT conferred good long-term stability and excellent interfacial compatibility on the MMMs. The results demonstrated that the composite filler with fast transport pathways designed in this study was an effective strategy to enhance gas separation performance of MMMs, verifying its application potential in the gas purification industry.Keywords:composite material;UiO-66;HNT;mixed matrix membrane;CO2/N2separation
研究领域:
材料科学
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化学工程
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DOI
PubMed
高影响因子
ACS Applied Energy Materials
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2019
·
IF 0
Ke Chu,Ya-ping Liu,Jing Wang,Hu Zhang
Current artificial NH3 synthesis relies heavily on the Haber–Bosch process that involves enormous energy consumption and huge CO2 emission. The electrochemical N2 reduction reaction (NRR) offers an eco-friendly and sustainable alternative but demands cost-effective and efficient NRR electrocatalysts. Herein, NiO nanodots (∼2 nm) supported on graphene (NiO/G) were developed as a high-performance NRR electrocatalyst at ambient conditions. Electrochemical tests indicated that the NiO/G exhibited a high NH3 yield (18.6 μg h–1 mg–1) and Faradaic efficiency (7.8%) at −0.7 V vs reversible hydrogen electrode, outperforming the most reported NRR electrocatalysts. Experimental and density functional theory (DFT) results revealed that NiO was the dominating active center, and nanodot structure enabled the NiO to expose more active sites. DFT results further demonstrated that the distal associative route was the preferable NRR pathway with *N2 → *NNH being the rate-determining step.
研究领域:
材料科学
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电催化
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能源与环境科学
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产品关联
DOI
危险品化学品经营许可证（带存储）