APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Jinxiu Zhao,Xuejing Liu,Xiang Ren,Xu Sun,Dongxu Tian,Qin Wei,Dan Wu
Electrochemical N 2 reduction is developing as an appealing carbon-neutral strategy for NH 3 artificial synthesis but seriously influenced by requiring high-efficiency electrocatalysts for the N 2 activation at ambient conditions. Here, we reported that defective-rich ZnS nanoparticles supported on reduced graphene oxide (DR ZnS-rGO) acts as a high-efficiency electrocatalyst for ambient N 2 -to-NH 3 conversion with excellent selectivity. In 0.1 M HCl, such DR ZnS-rGO presents a large NH 3 yield of 51.2 μg h –1 mg cat. –1 (−0.15 V vs . reversible hydrogen electrode, RHE) and a high faradic efficiency of 28.2 % (−0.10 V vs . RHE), as well as high electrochemical and structure stability. Isotopic labelling samples experiments reveal that the synthetic NH 3 directly arise from the supplied N 2 . Density functional theory calculations demonstrated that the engineering S vacancies in DR ZnS-rGO not only provide reaction sites for N 2 -to-NH 3 conversion but activate of N 2 molecules.
研究领域:
材料科学
·
电化学
·
催化
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2024
·
IF 5.3
Tongguo Huo,Dan Zhu,Jianxin Zheng,Yuan Lin,Yu Dai,Jian Wu
This study systematically investigated for the first time the effects of varying the temperature, pressure, C/Si molar ratio, and H 2 /Si molar ratio on β-SiC coatings produced via chemical vapor deposition (CVD) using the SiCl 4 –CH 4 –H 2 –N 2 system. Thermodynamic theoretical calculations were performed using the HSC Chemistry software. The temperature and C/Si molar ratio considerably affected the morphology, phase, and composition of β-SiC coatings. High-quality β-SiC coatings along the (111) crystal plane exhibiting a uniform surface, high density, low roughness, and good crystallinity were successfully synthesized at 1523.15 K and 200 Pa with a C/Si molar ratio of 1.0 and H 2 /Si molar ratio of 6.5. Additionally, when N 2 was used as the dilution gas instead of Ar, the resulting β-SiC coatings demonstrated reduced roughness, fewer free carbon, increased hardness (37.05 GPa vs. 39.19 GPa), enhanced modulus of elasticity (237.26 GPa vs. 264.24 GPa), and superior coating adhesion (16.48 MPa vs. 18.29 MPa).
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Zhaojie Wang,Qinglong Liu,Xinle Sun,Caifeng Xia,Qikang Yin,Maohuai Wang,Xiaodong Chen,Huili Zhang,Shuxian Wei,Xiaoqing Lu,Siyuan Liu
MOFs-filled mixed matrix membranes (MMMs) have great potential to break the trade-off effects of traditional gas separation membranes. However, achieving good interfacial compatibility and adequate dispersion of the MOF is not straightforward. In this study, a continuous postmodification was developed for advanced CO2/N2 MMMs. UiO-66-NH2 was easily modified with trimesoyl chloride (UiO-66-TMC) and polyethylene glycol (UiO-66-PEG) sequentially, which was utilized as fillers to construct polyimide (PI) mixed matrix membranes (MMMs). Rich interactions between modified UiO-66-NH2 and the PI polymer contribute to efficient CO2 and N2 separation. At 25 °C and 0.1 MPa, UiO-66-TMC/PI MMMs showed a CO2/N2 selectivity of 55.3, and a CO2 permeability of 616.17 Barrer, and those are 56.7 and 686 Barrer for UiO-66-PEG200/PI MMMs. Both of their CO2/N2 separation performances exceed the 2008 Robeson upper bound. The ether bonds in PEG exhibit strong interactions with the CO2 molecules and improve the CO2 dissolution selectivity. Meanwhile, the introduction of organic ingredients realized good dispersion and interfacial compatibility within the PI matrix. This work lays the groundwork for the further fabrication of highly selective CO2 separation materials with specific microscopic interface structures and properties.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Zhenjie Gu,Zibo Yang,Xiangyu Guo,Zhihua Qiao,Chongli Zhong
CH 4 /N 2 separation, a viable way to purify energy gas and reduce the greenhouse effect, requires the use of highly gas permeable membrane, but acid environment affects the membrane stability. In this work, the ZIF-8@VR nanoparticle was synthesized via a high vacuum resistance sintering method (VRSM), which increased the acid resistance to pH 2.8 because of surface carbonization and stiffening. The structure of the ZIF-8@VR nanoparticle was investigated by XRD, SEM, FTIR, BET and Raman analysis, followed by blending it with polyacrylic acid (PAA) to fabricate PAA/ZIF-8@VR mixed matrix membranes (MMMs). The MMMs exhibited excellent CH 4 permeance and satisfactory CH 4 /N 2 selectivity, with the optimal CH 4 permeance (~1763 GPU) for the MMM with 66.8 wt% ZIF-8@VR filler. Furthermore, compared with pure PAA membrane, the MMMs with ZIF-8@VR filler could improve the CH 4 /N 2 selectivity from 1.3 to 3.1.
研究领域:
材料科学
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化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2023
·
IF 9.5
Zhihong Lin,Ziyi Yuan,Kaifang Wang,Xuezhong He
Novel mixed matrix membranes (MMMs) with superior CO 2 /N 2 separation properties are of great importance for post-combustion CO 2 capture from flue gas . Metal-organic frameworks (MOFs) as one of the most attractive porous fillers for MMMs fabrication, are considered to provide a solid molecular sieving mechanism for enhancing CO 2 /N 2 selectivity. However, it causes the reduction in gas permeability and limits its further industrialization. Herein, we proposed a new strategy for filler functionalization by doping silver ions (Ag + ) into UiO-66-NH 2 nanoparticles through the double-solvent method and used for the preparation of advanced MMMs. The double-solvent method is benefits for the enrichment of Ag + in the hydrophilic pores of UiO-66-NH 2 . As a result, the prepared novel MMMs called Ag + @UiO@PIM-1 with the polymers of intrinsic microporosity (PIMs) as polymer matrix , show outstanding CO 2 permeability. According to the mixed gases (CO 2 /N 2 = 10:90) permeation experiments under 25 °C and 2 bar, the membrane with 30%Ag + @10%UiO loading achieves more than 65% increase in CO 2 /N 2 selectivity (∼30) and 120% in CO 2 permeability (>15,000 Barrer) compared to the pristine PIM-1 membrane. By optimizing the Ag + doping amount and Ag + @UiO loading content, the separation performance exceeds the 2019 CO 2 /N 2 upper bound. To figure out the separation mechanism, the pore texture properties and CO 2 affinity of the functional filler (Ag + @UiO) together with the membrane structure were characterized by XPS , PXRD , SEM, gas sorption , etc. The synergistic mechanisms by combing CO 2 facilitated transport and molecular sieving from pore regulation were identified to enable advanced CO 2 /N 2 membrane separation .
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Shuangqing Sun,Xiqiang Zhang,Shengxiang Feng,Hongbing Wang,Yan Wang,Jianhui Luo,Chunling Li,Songqing Hu
A novel CO 2 /N 2 switchable aqueous foam was developed using a CO 2 -responsive surfactant N,N-dimethyl-N-dodecyl amine (C 12 A) and a conventional surfactant sodium dodecyl sulfate (SDS). The performance and mechanism of this switchable foam were studied by both experiment and molecular simulation methods. Experimental results demonstrate that the foam stabilized by SDS/C 12 A surfactants has better stability and water carrying capacity than single C12A foam. The foam could be rapidly switched between stable and unstable states at ambient temperature with CO 2 or N 2 as the triggers. Simulation results shows that when CO 2 was introduced, most of SDS and C 12 A molecules aggregated in the water phase, instead of adsorbing at the air-water interface to stabilize the foam films. The strong electrostatic attraction between protonated C 12 A and SDS molecules could account for the aggregation. Due to the presence of limited surfactants located at the air-water interface after introducing CO 2 , the foam bursts quickly.
研究领域:
化学
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材料科学
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胶体与表面化学
·
分子模拟
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Feifei Zhang,Kunjie Li,Jian Chen,Xinran Zhang,Kebing Li,Hua Shang,Lei Ma,Wujie Guo,Xinlong Wu,Jiangfeng Yang,Jinping Li
Natural gas purification by economic and low-energy adsorptive separation processes is important. However, as a difficult global problem, N 2 removal from N 2 /CH 4 mixtures is challenging because of their similar physical properties. In this study, the separation of N 2 /CH 4 by Cr-metal–organic frameworks (MOFs) (MIL-100Cr, MIL-101Cr and TYUT-96Cr) with various open Cr site densities was studied. Gas sorption isotherms showed that TYUT-96Cr exhibited the highest N 2 /CH 4 uptake ratio (13.67 at 0.01 bar and 298 K) of the selected Cr-MOFs, which was consistent with the highest density of Cr (III) sites. This material provided the highest CH 4 productivity (0.716 mmol/cm 3 ) per cycle for N 2 removal from a 5:95 N 2 /CH 4 mixture to produce 99.99% pure CH 4 , as shown by the breakthrough experiments. Pressure-swing adsorption simulations indicated that, by a two-bed six-step method, pristine 95% methane was enriched to 98.9% by TYUT-96Cr. The largest CH 4 productivity, high breakthrough selectivity and thermal stability of TYUT-96Cr among the Cr-MOFs, made it a promising adsorbent in trace N 2 removal for practical industrial application.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2021
·
IF 5.455
Xiaowu Liang,Pengfei Wang,Congli Li,Min Yuan,Qi Shi,Jinxiang Dong
CO is an important raw material and the separation of CO/N 2 in blast furnace gas can supply an abundant source of CO. Metal organic frameworks (MOFs) containing open metal sites are capable of selectively binding to CO over N 2 . However, the open metal sites easily bind to guest molecules during the preparation and activation process. In this study, typical MOFs containing open metal sites (Co-MOF-74) were used to investigate the activation behavior and corresponding CO/N 2 adsorptive separation performance. To characterize the removal and decomposition of guest molecules, TG-MS and NMR analysis of MOF-74 prepared under different activation conditions were performed. During the heat and vacuum process, the guest H 2 O and methanol (MeOH) molecules in Co-MOF-74 were first removed at 150 °C under vacuum. The aim of high temperature activation at 300 °C is the decomposition of a small amount of bind N,N-dimethylformamide (DMF) and terminal ligands occupying the open metal sites in Co-MOF-74. In addition, H 2 O molecules occupy the open metal sites of Co-MOF-74 during the filtration and MeOH wash steps under air, which is accompanied by the removal of a portion of DMF. The CO adsorption (298 K and 1 bar) and the CO/N 2 selectivity (Ideal adsorbed solution theory: 50:50, v/v) of Co-MOF-74 activated at 300 °C was 6.07 mmol/g and 384, respectively, which was higher than that of the other activated Co-MOF-74 samples and was attributed to the effective removal of guest molecules. Our results may guide the activation of MOFs, which contain open metal sites.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Hongchun Sun,Cui Dong,Chao Feng,Hui Wang,Zhenping Qu
Co 3 O 4 catalysts possess high activity in selective catalytic oxidation of NH 3 (NH 3 -SCO), but the low N 2 selectivity hinders their potential application. To enhance N 2 selectivity, the chemical bonded Nb-O-Co catalyst by the deposition of Nb species onto Co 3 O 4 (Nb/Co 3 O 4 -0.03) is constructed. It shows 100 % NH 3 conversion and 82 % N 2 selectivity at 180°C, and the N 2 selectivity is 2.2-fold higher than that of Co 3 O 4 (38 %). The failure of enhancement in N 2 selectivity for physically mixed Co 3 O 4 and NbO x (NbO x |Co 3 O 4 -0.03) further indicates the crucial role of chemical bonded Nb-O-Co in enhancing N 2 selectivity. In situ diffuse reflectance infrared Fourier transform spectra and NH 3 temperature-programmed desorption results show the formation of new NH 3 adsorption sites. Importantly, intermediates NO - stabled on Nb/Co 3 O 4 -0.03 tends to react with -NH 2 to produce N 2 through internal selective catalytic reduction (iSCR). This work offers insights into enhancing the N 2 selectivity in NH 3 -SCO and advances understanding of iSCR mechanism.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Chengli Jiao,Zedong Li,Xinxin Li,Mian Wu,Heqing Jiang
Poor interfacial compatibility that often led to low gas separation performance is one of key challenges for developing composite membranes. In the present study, nanosized polyethyleneimine (PEI) functionalized ZIF-8 (PEI-ZIF-8) with good dispersion, having a particle size around 15 nm, has been synthesized via in-situ method and used as filler to fabricate Pebax/PEI-ZIF-8 composite membranes. Excluding the intrinsic porous structure and higher affinity with CO 2 of PEI-ZIF-8 beneficial for CO 2 selective transport, the large density of amine groups on PEI chains provide a good interfacial compatibility, and introduce facilitated CO 2 transport path. Furthermore, PEI-ZIF-8 reduces the crystallinity of Pebax matrix, which is favorable for CO 2 transport. The composite membrane with 5 wt% PEI-ZIF-8 shows a CO 2 permeance of 13.0 GPU with a CO 2 /N 2 selectivity of 49.0, which increases by 80.6% and 118.8% respectively in contrast with pristine Pebax membrane. The results demonstrate that nanoparticles functionalized by amine-polymer with long chains is effective for constructing composite membranes with good interfacial compatibility.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2019
·
IF 4.63
Yuxing Wang,Qingji Ying,Yaoyu Zhang,Yue Liu,Zhongbiao Wu
In this paper, the reaction behaviors of CH 3 CN catalytic combustion over CuCeO x -HZSM-5 catalysts prepared by the physical mixing and wet impregnation methods were investigated. The experimental results had revealed that the composite catalysts exhibited excellent degradation efficiency and high N 2 selectivity: the Cu-Ce oxides ensured the high activity, and the introduction of HZSM-5 limited the formation of NO x . The involved reaction mechanism was then studied by an in situ DRIFT analysis. It could be deduced that different reaction pathways would occur over CuCeO x and HZSM-5. The catalytic reaction over CuCeO x mainly proceeded via an oxidation pathway. The CN group could be converted to isocyanate species [NCO(a)] which would be further oxidized to NO x . Over HZSM-5, CH 3 CN was mainly hydrolyzed into ammonia. For the CuCeO x -HZSM-5 composite catalysts, the over-oxidation of NCO(a) and NH 3 was inhibited, and an internal selective catalytic reduction (SCR) reaction could occur, thereby greatly improving the N 2 selectivity.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Shuang Ni,Li Xu,Xi-Ting Zhang,Shao-Min Wang,Qing-Yuan Yang
Efficient and economical capture and separation of sulfur hexafluoride (SF6) are critical for emissions mitigation and industrial reuse. Conventional distillation methods remain energy-intensive, prompting the need for cost-effective alternatives. Here, MOF-303, constructed from earth-abundant aluminum and low-cost linkers, features optimally sized pores (8.3 Å) that selectively adsorb SF6 (5.5 Å) over N2 (3.6 Å). This rational pore engineering enables MOF-303 to achieve benchmark SF6 capture (1.91 mmol g–1 at P < 0.1 bar) with exceptional selectivity (148), while its low regeneration energy (22.9 kJ mol–1) ensures practical cycling. Breakthrough experiments confirm robust performance under dynamic conditions. Computational studies reveal how pore geometry enables size-exclusive recognition. Compared to noble-metal adsorbents, MOF-303’s earth-abundant components reduce costs by >70%, offering a sustainable solution for industrial SF6 recovery.
研究领域:
环境科学
·
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）