HIGH PERFORMANCE POLYMERS
·
2025
·
IF 1.6
Zhiqing Liang,Zhongying Liu,Xiuyuan Wei,Hui Wu,Chanjuan Liu,Xiaohua Huang
Bifunctionalized NH2-UiO-66-CF3 nanofillers were successfully prepared by grafting - CF3 on NH2-UiO-66 via aldehyde-amine condensation reaction and applied to the preparation of 6FDA-ODA/NH2-UiO-66-CF3 mixed matrix membranes (MMMs). The successful introduction of -NH2 and -CF3 groups was verified by FT-IR, XRD, and XPS characterization, and the integrity of the crystal structure was ensured. Due to the presence of hydrogen bonding, NH2-UiO-66-CF3 showed good interfacial compatibility with the polymer matrix. Due to the introduction of the - CF3 group, the MMMs exhibited excellent thermal stability (T10% > 500°C, Tg = 300°C–305°C), hydrophobicity (contact angle of 92.96–97.71), and mechanical properties (tensile strength of 74–85 MPa). The gas separation performance tests showed that the MMMs exhibited significantly improved gas permeability and selectivity compared to the pure 6FDA-ODA membranes, which was attributed to the fact that the -NH2 and -CF3 groups provided more adsorption sites for gases. In particular, the PI/NUF(10) MMMs showed the best performance, with permeabilities of 42.71, 9.22, and 92.79 Barrer for CO2, O2, and He, respectively, which were 248%, 213%, and 173% higher than those of the pure membranes. Meanwhile, the selectivities of CO2/N2, O2/N2 and He/N2 were improved by 37%, 24%, and 8%, respectively. Close to the Robeson upper limit, demonstrating excellent gas separation potential.
研究领域:
材料科学
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化学工程
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膜技术
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气体分离
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纳米技术
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 43
·20777-20785
·
IF 3.925
Yanke Yu,Mengqiao Geng,Desheng Wei,Chi He
Selective catalytic oxidation of NH3 (NH3-SCO) is a promising method to reduce NH3 pollution. The Pt-based catalysts exhibited excellent activity in the NH3-SCO reaction under low temperatures. However, it was easy for the NH3 to be oxidized to N2O and NOx (NO and NO2) over the Pt-based catalyst, causing a low N2 selectivity. The CuSO4, which could supply both Brønsted and Lewis acid sites on the catalyst, was used to promote N2 selectivity. The N2 adsorption–desorption, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), inductively coupled plasma mass spectrometry (ICP-MS), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), NH3-temperature programmed desorption (NH3-TPD), H2-temperature programmed reduction (H2-TPR) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) were used to characterize the catalyst. The addition of CuSO4 could suppress the formation of N2O and NOx, thus the highest N2 selectivity on the catalyst increased from 21.2% to 78.1%. An imide mechanism was the main reaction mechanism on the Pt/TiO2 catalyst. After adding CuSO4, the NH3-SCO reaction over the CuSO4-Pt/TiO2 catalyst mainly followed an i-SCR mechanism where NH3 was oxidized to N2O and NOx, and then the newly formed N2O and NOx were reacted with NH3/NH4+ adsorbed on the Lewis and Brønsted acid sites via an NH3-SCR reaction over the catalyst, and finally N2 was formed. The acid sites performed an important role in the formation of N2 and this work should provide an effective method to promote N2 selectivity in a NH3-SCO reaction.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Zewen Xu,Pei Li,Hao Guo,Shengchao Zhao,Kuo Chen,Xinliang Liu,Ming Wang,Yingfei Hou
Excessive carbon emission leads to global warming, threatening human survival. Membrane-based carbon capture technology is an important component of carbon capture, utilization, and storage (CCUS) technology and one of the main upstream technologies for achieving carbon neutrality. PIM-1 materials exhibit high CO 2 permeability but lower CO 2 /N 2 selectivity, making it a significant focus to improve CO 2 /N 2 selectivity without sacrificing CO 2 permeability. In this work, Noria was introduced as a block through the bottom-up approach into the PIM-1 molecular chain, forming Noria-based porous organic polymer (NPOP) microregions with excellent CO 2 affinity. Additionally, the presence of NPOP increases the interchain gaps, resulting in a higher free volume. Consequently, the separation membrane prepared under optimal conditions broke the 2008 upper bound, with a 43.6 % increase in CO 2 permeability and a 41.7 % increase in CO 2 /N 2 selectivity. Furthermore, NPOP could form colloidal networks and provide rigidity to the separation membrane, endowing it with excellent aging resistance. After 6 months of aging, the CO 2 permeability of 0.5 %Noria decreased by only 33.4 % (67.4 % for pure PIM-1), indicating its strong potential for widespread applications.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Shaomian Liu,Wenjuan Xue,Yongjun Ji,Wenqing Xu,Wenxing Chen,Lihua Jia,Tingyu Zhu,Ziyi Zhong,Guangwen Xu,Donghai Mei,Fabing Su
Simultaneously improving both NO x conversion and N 2 selectivity in the selective catalytic reduction of NO by CO (CO-SCR) under O 2 -containing conditions is highly challenging because of the competitive reactions of NO x and CO with O 2 . Here, we demonstrate that the interfacial oxygen vacancies (IOVs) generated at the Co 3 O 4 -CeO 2 heterointerfaces by ball-milling-induced strain can remarkably boost both NO x conversion and N 2 selectivity in the temperature range of 100–400 °C. The Co 3 O 4 -CeO 2 -IOV catalyst achieved approximately 100% NO x conversion and 100% N 2 selectivity (200–350 °C, 1–5 vol% O 2 , and 20,000 h −1 ); even under 10 vol% O 2 , it still showed good catalytic performance. The spectroscopy analysis and theoretical calculations reveal that compared with O 2 activation, IOVs are more favorable for the rate-limiting step of NO adsorption and dissociation. This work provides an effective strategy to create IOVs within metal oxide composite catalysts using ball-milling-induced interfacial strain for improving CO-SCR performance.
研究领域:
材料科学
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环境催化
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Chuanzhi Sun,Hao Liu,Wei Chen,Dezhan Chen,Shuohan Yu,Annai Liu,Lin Dong,Shuai Feng
A series of Sm- and/or Zr-doped MnO x -TiO 2 catalysts were prepared, and the catalysts exhibited better N 2 selectivity and SO 2 resistance than the undoped MnO x -TiO 2 catalyst for the selective catalytic reduction of NO by NH 3 (NH 3 -SCR). The reasons for the good N 2 selectivity and SO 2 resistance of the catalysts were proposed. X-ray photoelectron spectroscopy (XPS) combined with density functional theory (DFT) calculations suggested that electron transfer between the manganese and samarium species by Mn 4+ + Sm 2+ ↔ Mn 3+ + Sm 3+ redox cycles occurred in the Sm-containing catalysts. Furthermore, electron transfer from Sm 2+ to Mn 4+ suppressed electron transfer from NH 3 to Mn 4+ , inhibiting the formation of NH 2 or NH. Thus, the pathway for NH generation was removed, and the reaction of 2NH + 4NO → 3N 2 O + H 2 O was prevented. Consequently, the N 2 selectivity of the NH 3 -SCR reaction was enhanced. In situ diffused reflectance infrared Fourier transform spectroscopy ( in situ DRIFTS) combined with thermogravimetry, differential scanning calorimetry and mass spectrometry (TG-DSC-MS) results revealed that the deposition rate of sulfate species decreases after Sm doping, which was also attributed to the suppressed electron transfer from SO 2 to Mn 4+ , i.e., the oxidation of SO 2 to SO 3 . Thus, the catalysts exhibited better SO 2 resistance.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yaoyu Zhang,Yuxiong Wang,Yue Liu,Huimin Xu,Zhongbiao Wu
Aiming at the coexistence of pollutants in the actual industrial process, the catalytic oxidation of acetonitrile and ethyl acetate mixture on the Cu–Ce/ZSM–5 catalyst was studied. The mutual inhibition effect during catalytic removal of acetonitrile and ethyl acetate mixture was observed. Acetonitrile showed a more obvious inhibitory effect on the conversion of ethyl acetate, and the introduction of ethyl acetate reduced the N 2 selectivity of acetonitrile oxidation. The simulation results demonstrated acetonitrile could be preferentially adsorbed on Cu center of the catalyst surface, leading to significant inhibition of the initial conversion of ethyl acetate. In addition, the coexistence of ethyl acetate would weaken the hydrolysis of acetonitrile to generate carboxylic acid and –NH x species. As such, no enough adsorbed NH x species could be used to reduce the NO x produced by excessive oxidation of acetonitrile, resulting in a decreased in N 2 selectivity. This study could provide reference on the application of catalysts for cyanide–containing waste gas degradation.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Qiaobo Liao,Haocheng Xu,Can Ke,Yiying Zhang,Qingwen Han,Yifan Zhang,Yang Xu,Ding Wang,Kai Xi
Sulfur hexafluoride (SF 6 ) is the most potent greenhouse gas whose emission is in great need of reduction during industrial processes. Here, a variety of imine-linked covalent organic frameworks with varying surface areas, pore size distributions, and topologies are rationally designed and regulated for systematically studying structure–property relationships of COF-based SF 6 adsorbents. In terms of imine-linked COFs without further modification, the surface area was found to be a prerequisite for achieving high SF 6 uptakes, and a small pore size at ca. 0.9 nm could effectively strengthen the adsorbate-adsorbent interaction and hence enhance the SF 6 /N 2 selectivity. With a large specific surface area, suitable pore size, and strong covalent bonds, RCOF-1 showed superior SF 6 adsorption capacities up to 4.13 mmol g −1 and large SF 6 /N 2 selectivity up to 125 (273 K, 100 kPa) accompanied by excellent stability, which can be considered one of the most high-performance porous materials for SF 6 capture and separation. This work not only provides a series of high-performance SF 6 adsorbents but also broadens the horizon of applications of the emerging COFs, pointing out their development direction in the field of SF 6 capture and separation.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2023
·
IF 6.9
Songjin Ko,Xiaolong Tang,Fengyu Gao,Honghong Yi,Hengheng Liu,Ning Luo
In this work, the phosphomolybdate (HPMo) modification strategy was applied to improve the N 2 selectivity of MnCo-BTC@SiO 2 catalyst for the selective catalytic reduction of NO x , and further, the mechanism of HPMo modification on enhanced catalytic performance was explored. Among MnCo-BTC@SiO 2 -x catalysts with different HPMo concentrations, MnCo-BTC@SiO 2 -0.75 catalyst exhibited not only the highest NH 3 -SCR performance (∼95% at 200-300°C) but also the best N 2 selectivity (exceed 80% at 100-300°C) due to the appropriate redox capacity, greater surface acidity. X-ray photoelectron spectrometer (XPS) and temperature programmed reduction of H 2 (H 2 -TPR) results showed that the modification with HPMo reduced the oxidation-reduction performance of the catalyst due to electron transfer from Mo 5+ to Mn 4+ /Mn 3+ and prevent the excessive oxidation of ammonia adsorption species. NH 3 temperature-programmed desorption of (NH 3 -TPD) results showed that the modification with HPMo could significantly improve the surface acidity and NH 3 adsorption, which enhance the catalytic activity and N 2 selectivity. In-situ diffused reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) revealed that modification with HPMo increased significantly the amount of adsorbed NH 3 species on the Bronsted acid site and C B / C L , it suppressed the production of N 2 O by inhibiting the production of NH species, the deep dehydrogenation of ammonia adsorption species. This study provided a simple design strategy for the catalyst to improve the low-temperature catalytic performance and N 2 selectivity.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
PubMed
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
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DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Lin-Cong He,Hua-Hui Xu,Xing-Yue Leng,Ling-Yun Jin,Ai-Ping Jia,Meng-Fei Luo,Jian Chen
Selective catalytic oxidation of nitrogen containing volatile organic compounds (NVOCs) is very meaningful but still remains big challenge because it is very difficult to balance the oxidation activity and N 2 selectivity of available catalysts. In order to develop excellent catalysts with high N 2 selectivity in wide temperature window ( △T ) during NVOCs oxidation, CeO 2 modified CuO/ZSM-5 catalysts with different CeO 2 addition order were prepared for diethylamine (DEA) oxidation. Detailed characterizations of catalysts such as XRD, XPS, H 2 -TPR and NH 3 -TPD were conducted, it is found that addition of CeO 2 obviously changes the geometrical and electronic states of CuO active sites in the catalyst, and CeO 2 addition order affects the Ce 3+ ratio on the catalyst surface. Promotion of CeO 2 species enables the generation of more highly active Cu species (Cu + species and finely dispersed CuO clusters) for DEA oxidation; and synergistic catalysis of the Ce 3+ species, active Cu species and acid sites in ZSM-5 leads to the high N 2 selectivity in wide temperature window ( △T ). Compared to the CeO 2 /CuO/ZSM-5 and CuO-CeO 2 /ZSM-5 catalysts, the CuO/CeO 2 /ZSM-5 catalyst exhibits moderate high oxidation activity with T 99 of 230 °C and the widest △T of 150 °C for high N 2 selectivity. Our primary results in this work provide the efficient strategy for improving catalyst employed for NVOCs selective oxidation.
研究领域:
催化化学
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环境科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2023
·
IF 5.5
Yaoyu Zhang,Yuxiong Wang,Yue Liu,Yuxing Wang,Ling Zhou,Huimin Xu,Zhongbiao Wu
A series of Cu-based catalysts with different types of supports (TiO 2 , Al 2 O 3 , S-1, HZSM-5 SiO 2 /Al 2 O 3 = 27 and 85) were investigated for selective catalytic combustion of acetonitrile (CH 3 CN). Among all catalysts, the Cu/TiO 2 and Cu/Al 2 O 3 catalysts had superior activity accompanied with the generation of massive NO x , while Cu/ZSM-5 catalysts exhibited excellent N 2 selectivity. The characterization results indicated that the surface acidity of catalysts played a decisive role in reaction behavior. For the Cu/TiO 2 and Cu/Al 2 O 3 catalysts mainly with Lewis acid sites, CH 3 CN underwent an initial hydrolysis step with surface hydroxy group to form acetamide anion (CH 3 CONH ad ), then occurred further hydrolysis reaction to form NH 3 at low temperatures, or turned to proceed oxidation reaction with numerous NO x generation at high temperatures. Whereas, the enriched Brønsted acid sites on the Cu/ZSM-5 catalysts brought abundant isolated Cu 2+ ions, which guaranteed the processing of iSCR reaction, thereby promoting the occurrence of hydrolysis and oxidation reaction pathways in parallel and benefiting the improvement of N 2 selectivity. These results elucidated the influence of supports with different acidic types in reaction pathway and provided precious reference for the development of high-performance NVOCs catalysts.
研究领域:
环境科学
·
催化化学
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产品关联
DOI
高影响因子
Green Chemical Engineering
·
2021
·
IF 0
Qingping Xin,Xueting Cao,Dandan Huang,Shuo Li,Xinghui Zhang,Guangyu Xuan,Mengting Wei,Lei Zhang,Xiaoli Ding,Yuzhong Zhang
One type of new light-responsive hierarchical metal organic framework (MOF) has been successfully prepared using Co(NO 3 ) 3 ·6H 2 O as the metal salt and 4,4′-azobenzenedicarboxylic acid as the ligand by microwave method for the first time. It is found that MOF [Co(AzDC)] exhibits a light-responsive characteristic to SO 2 adsorption due to the presence of azo group from the ligand. The light-responsive hierarchical MOFs are incorporated into Matrimid® 5218 (PI) matrix to prepare mixed matrix membranes (MMMs) for gas separation application. The morphology, crystallinity, chain mobility and thermal stability of MMMs are explored. Results show that Co(AzDC) may elevate both the CO 2 (SO 2 ) permeability and CO 2 (SO 2 )/N 2 selectivity of the MMMs. In particular, the Co(AzDC) doped MMMs exhibit the significantly improved CO 2 (SO 2 )/N 2 selectivity from 33 (123) for PI control membrane to 78 (420) for MMMs, overcoming the 2008 Robeson upper bound for CO 2 /N 2 system. Size-sieving effect of Co(AzDC) with pore size 0.35 nm enhances the selectivity, while the –N=N– group from Co(AzDC) shows affinity to CO 2 molecular rather than N 2 , also elevating selectivity of MMMs. In brief, enhanced selectivity of high-performance membrane is attributed to incorporation of Co(AzDC) particles, which displays synergistic effects both in size-sieving and CO 2 -philic interaction for CO 2 /N 2 separation. Smart highly selective interface is constructed in MMMs by switching the configuration of MOFs from cis to trans . The SO 2 permeability and SO 2 /N 2 selectivity of MMMs are investigated under both visible light and ultraviolet light states, and the SO 2 /N 2 separation performance under visible light is notably improved in comparison with that under ultraviolet light state.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
危险品化学品经营许可证（带存储）