Journal of Physical Chemistry C
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2021
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IF 4.126
Shichao Han,Xiaomin Tang,Ye Ma,Qinming Wu,Jiaqi Shi,Jian Li,Xiangju Meng,Anmin Zheng,Feng-Shou Xiao
The selective catalytic reduction of nitrogen oxide with methane (CH4–SCR) has been considered as an alternative technology for the simultaneous removal of NOx and CH4, and one of the efficient catalysts for this reaction is Co-exchanged SSZ-13 (Co-SSZ-13) zeolite catalyst. However, the preparation of the Co-SSZ-13 zeolite catalyst is costly due to the use of an expensive organic template and Co exchange. We demonstrate here the design of a low-cost cobalt–amine complex (Co–DETA) as a novel structure-directing agent (SDA) for the one-pot synthesis of Co-SSZ-13 zeolite with the assistance of theoretical calculations. Physicochemical characterizations including X-ray diffraction, scanning electron microscopy, N2 sorption, and magic-angle spinning nuclear magnetic resonance show that the Co-SSZ-13 zeolite has good crystallinity, a cubic morphology, a high surface area, and four-coordinated aluminum species. Furthermore, thermogravimetry–differential thermal analysis, Fourier transform infrared spectroscopy, and diffuse reflectance ultraviolet–visible spectroscopy confirm that the Co–DETA complex acts as a SDA for the synthesis of Co-SSZ-13 zeolite. More importantly, the Co-SSZ-13 zeolite exhibits good catalytic performance in the CH4–SCR reaction with 10% H2O in the feed gas stream. The efficient and facile synthesis of Co-SSZ-13 zeolite plus its good catalytic performance might offer a good opportunity for its industrial applications in the future.
研究领域:
材料科学
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环境科学
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催化化学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
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2024
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IF 4.4
Chunlai Zhang,Yingdong Hao,Xingbo Wang,Deng Hu,Nannan Sun,Wei Wei
Photocatalysis is a highly promising strategy for the direct conversion of inert methane (CH4). In this study, a ZnO semiconductor with a nanorod morphology (r-ZnO) was synthesized using a template-directed hydrothermal method, which was further used to prepare nAg/r-ZnO photocatalysts through impregnation and reduction. The structure, composition, and microstructure of nAg/r-ZnO were characterized using techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and UV-visible absorption spectroscopy (UV-vis). The in-depth mechanism of the photocatalytic conversion of CH4 was revealed through electron paramagnetic resonance (EPR) and radical capture experiments. The results showed that the introduction of Ag species promoted the separation of photoinduced electron (e−) and hole (h+) pairs, which facilitated the generation of reactive oxygen species (ROS). Therefore, the performance of photocatalytic CH4 oxidation can be significantly enhanced. Interestingly, formaldehyde (HCHO) was generated as the primary product instead of low-value methanol (CH3OH). Through optimization of Ag loading and reaction conditions, an excellent oxygenate (CH3OOH, CH3OH, and HCHO) yield of 15 551.60 μmol g−1 h−1 with a high selectivity of 98.46% was achieved simultaneously, which has been rarely reported in previous studies.
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
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
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IF 4.9
Yaru Shen,Jiasheng Cai,Xin Huang,Yi Zheng,Yu Shao
Photocatalysis is a green technology which could sustainably convert CO 2 into value-added chemicals by using solar energy. Under xenon light irradiation, Mn 2 O 3 /MgTi 2 O 5 nanocomposites synthesized by two-step hydrothermal method greatly increase photocatalytic activity of CO 2 reduction. The optimal yield 420.53 μmol g −1 h −1 for CH 4 is achieved at a ratio 1:10 (W/W) of Mn 2 O 3 to MgTi 2 O 5 , with selectivity of 98.1 %, i.e., 4 and 33 times larger than those of individual MgTi 2 O 5 and Mn 2 O 3 , respectively. The superior photocatalytic performance is attributed to the formation of S-type heterojunction, valence change of Mn 3+ /Mn 4+ , and the bridging effect of Mg migration, which facilitates the separation and transfer of photogenerated electrons and holes. Mn 2 O 3 /MgTi 2 O 5 constructs an efficient redox photocatalytic system composed of a light trapping component (Mn 2 O 3 ), electron transport channel (Mg penetrating Mn 2 O 3 ), mutually separated reduction center (MgTi 2 O 5 ) and oxidation center (Mn 2 O 3 ). The potential Mn 2 O 3 /MgTi 2 O 5 photocatalyst for CO 2 reduction provides new insights to design novel efficient photocatalyst composites akin to biological photosynthesis.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2024
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IF 8.1
Jianing Mao,Guanghui Feng,Xiao Dong,Ziran Xu,Bingbao Mei,Yiheng Wei,Xiaohu Liu,Guihua Li,Shoujie Li,Yanfang Song,Fei Song,Wei Wei,Wei Chen,Zheng Jiang
CH 4 , as an important clean fuel and hydrogen carrier, its production from CO 2 driven by renewable energy could simultaneously achieve energy supply, CO 2 emission reduction, and renewable energy consumption, which is of great significance. Electrocatalytic CH 4 production relies on high-valence Cu species for realizing multielectron reduction, while facing inadequate performance stability due to the reconstruction tendency of Cu. Herein, an amorphous CuO x -SiO 2 catalyst (amorCuO x -SiO 2 ) is synthesized via an electrostatic interaction strategy to construct stable Cu 2+ active sites for efficient electrocatalytic CH 4 production. AmorCuO x -SiO 2 shows a good reconstruction resistance during electroreduction, confirmed via X-ray absorption spectroscopy studies, endowing a 63.7% CH 4 faradaic efficiency at 500 mA cm −2 , which is 7.8 folds of crystalized CuO x -SiO 2 (crysCuO x -SiO 2 ). Theoretical calculations revealed that stable Cu 2+ active sites enhanced *CO adsorption and were more susceptible for further hydrogenation, thus promoting the CO 2 -to-CH 4 conversion. Our findings provide a feasible strategy for developing reconstruction-resistant electrocatalysts for advanced CH 4 production performance.
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
HIGH PERFORMANCE POLYMERS
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2021
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IF 2.161
Tao Yang,Hongchang Pang,Zan Chen,Cuijia Duan,Biao Yuan,Shuo Yan
A series of hyperbranched copolyimides (co-HBPIs), as the completely symmetrical tetraamine monomer successfully incorporated into the linear polyimide 6FDA-ODA, were synthesized under the chemical imidization after the gel formation was avoided, as to more effectively separate CO2/CH4. CO2/CH4 selectivity (74%) was observed to be improved significantly under 7‰ tetraamine contents at 2 bar and 35°C; thus, the acceptable CO2 permeability was maintained compared with the pure membrane, exceeding the 1991 upper bound. Moreover, the as-prepared membrane with 6FDA-ODA-7‰ was reported to exhibit higher CO2/CH4 selectivity (109.14) at 10 bar and 35°C. Accordingly, the hyperbranched copolyimides will be promising candidates as membrane materials for the further separation of CO2/CH4 gas pair.
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2015
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IF 2.037
Yu Zhang,Wei Su,Yan Sun,Jia Liu,Xiuwu Liu,Xiaojing Wang
MIL-101 is a promising adsorbent because of its large pore volume, high separation selectivity, easy regeneration, and good stability. MIL-101 was synthesized and characterized by X-ray diffraction, scanning electron microscopy, and nitrogen adsorption at 77 K. Adsorption isotherms of pure N2, CH4, and CO2 were measured on MIL-101 from 263 K to 313 K and at pressures up to 0.8 MPa. The Langmuir model was a good fit for the experimental isotherms and the isosteric heats of adsorption decreased in the order: CO2 > CH4 > N2. The CO2/CH4 separation selectivity was sensitive to the adsorption pressure and temperature and it varied from 3.2 to 6.3. In contrast, the CH4/N2 separation selectivity changed from 2.6 to 3.3 with temperature and pressure.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
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IF 22.1
Jiangyong Yuan,Chunqiang Lu,Zhenhua Gu,Jun Cai,Han Zhao,Danyang Li,Lei Jiang,Haiwen Xu,Zhi qiang Li,Kongzhai Li
Carbon cycling, instead of conventional oxygen cycling in chemical looping, overcomes the limitations of oxygen storage capacity of oxygen carriers and enables the reaction to proceed under relatively mild conditions. In this study, we designed a high-performance carbon-storage catalyst (Ni-Co/Al 2 O 3 ) for chemical looping conversion of CH 4 and CO 2 to H 2 and CO. The physico-chemical characterizations suggested that the Co alloyed with Ni could result in larger active metal particles and simultaneously benefit the bending of carbon deposits toward the periphery of the active sites, avoiding the quick deactivation of catalysts due to the encapsulation of the active sites by carbon deposits and generating a higher carbon capacity (23.59 vs. 14.08 mol/kg). In addition, the alloying of Co with Ni could weaken the graphitization of carbon deposits, thus facilitating the carbon elimination and catalyst regeneration in the CO 2 conversion step, strongly improving the cycling stability during long-term testing.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2023
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IF 9.5
Xi Chen,Nana Wang,Guining Chen,Zhenggang Wang,Gongping Liu,Rongfei Zhou,Wanqin Jin
Mixed-matrix formulation is a promising method to overcome permeability-selectivity trade-off of polymers with incorporation of fillers with well-defined nanopores . The filler properties play a key role in determining the performance of mixed-matrix membrane (MMM). In this work, for the first time, we explored the critical effect of filler structural integrity on separation performance of MMM. Typically, micron as-synthesized, submicron as-synthesized and submicron ground SAPO-34 zeolites were incorporated into 6FDA-DAM polyimide , respectively. The interface compatibility between two phases was ensured by (3-aminopropyl) trimethoxysilane (APTMS) modification on SAPO-34 fillers. It was found that the directly synthesized micron and submicron fillers contributed to enhance the CO 2 /CH 4 separation performance whereas the submicron ground filler lowered the CO 2 permeability. Notably, incorporating 30 wt% micron as-synthesized SAPO-34 into 6FDA-DAM enhanced the CO 2 permeability by 68% and CO 2 /CH 4 by 37%, surpassing the performance upper-bound. Moreover, the hydrogen bonding between the filler and polymer matrix endowed the membrane with outstanding plasticization resistance with CO 2 partial pressure up to 20 bar. Adsorption isotherms and Maxwell model prediction revealed that the filler transport properties could be significantly affected by commonly-used methods of reducing the filler size. A decreased structural integrity was identified in the sequence of micron as-synthesized, submicron as-synthesized and submicron ground fillers. This work highlights the importance of a careful balance between structural integrity and crystal size of filler, and reliable routes to obtain nanofillers with desirable structural integrity as pursuing high-performing MMM toward practical application.
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
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Caijiao Yu,Yueyao Liang,Xiangyu Guo,Zhihua Qiao,Chongli Zhong
Metal-organic framework (MOF)-mixed matrix membranes (MMMs) have the potential to overcome the trade-off limitations between gas separation performance and large-scale fabrication. However, most conventional MOF MMMs are used for CH 4 /N 2 separation systems, the preparation of MOF-MMMs with high permeance and good selectivity for N 2 /CH 4 separation has rarely been reported. Here in, we propose supported thin MOF-MMMs with abundant open metal sites to preferentially adsorb N 2 and improve the N 2 /CH 4 separation performance. The formation of the selectivity layer with abundant open metal sites was realized through dual-induction mechanism of in-situ Co 2+ ion doping and polydimethylsiloxane (PDMS) solution post-modification. The introduction of Co 2+ ions restricted the coordination of Zn-N and increased the number of open metal sites in the ZIF layer during its formation. The post-treated PDMS solution with weak acid could further induce the formation of open metal sites. Meanwhile, the electron paramagnetic resonance and synchrotron radiation-based XAFS results also confirmed that the number of open metal sites in the separation layer increased gradually with the in-situ Co 2+ ion decoration and PDMS solution post-modification. In addition, the PDMS also could repair the intercrystalline defects of the MOF membranes and reduce their non-selectivity area. Therefore, the synthesized ZIF-8 MMMs showed a high N 2 permeance of 1367 GPU and a moderate N 2 /CH 4 selectivity of up to 6.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2022
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IF 24.319
Honglin Li,Shoufu Cao,Hongman Sun,Yonglian Lu,Ying Zhang,Xiaoqing Lu,Jingbin Zeng,Zifeng Yan
Copper (Cu) has been proved as an efficient catalyst in carbon dioxide electrochemical reduction reaction (CO 2 RR) towards hydrocarbons, but still suffers from low selectivity and poor stability. Herein, Cu-based/CxNy catalysts were fabricated by facile pyrolysis of CuNCN in sealed quartz tubes. It is found that CuNCN pyrolyzed at 300 °C (CuNCN-300) exhibits a high C 2 H 4 Faradaic efficiency of 48.5% at 500 mA cm - 2 . However, increasing the pyrolysis temperature above 400 °C gives rise to CH 4 being the predominant product and CuNCN-500 achieves CH 4 Faradaic efficiencies of 66.3% at 300 mA cm - 2 . Combining experimental and DFT calculation results, Cu 3 N plays a crucial role in the formation of C 2 H 4 , while tri-s-triazine units in CuNCN-500 reduce the barrier of *CO hydrogenation to *CHO and retard C-C coupling on Cu surface. These findings mark the significance of precise tailoring of the synergistic effect between g-C 3 N 4 and different Cu species for achieving the desired selectivity during CO 2 RR.
研究领域:
材料科学
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电化学
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理论计算
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
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2025
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IF 4.2
Shanshan Liu,Dongxu Huang,Yong Pan,Zhenhua Wang,Juncheng Jiang
This study employs laser schlieren imaging and pressure measurement techniques to investigate the impact of kaoline (Ko) on the explosion behavior of CH 4 /H 2 mixtures at various equivalence ratios (0.8, 1.0 and 1.2) and H 2 contents (0, 0.3 and 0.9). Results indicate that the inhibitory effect of Ko first increases and then decreases with increasing concentration, achieving optimal suppression at 175 g/m 3 . Under the same equivalent ratios ( φ ), the reduction in maximum explosion pressure ( P max ) becomes more pronounced with higher H 2 addition ( R ). At constant R but varying φ , the suppression effect exhibits a different trend: when R =0 and 0.3, optimal suppression occurs at φ =0.8. Whereas at R =0.9, the optimal suppression effect is observed at φ =1.0, corresponding to a 30.27% reduction in P max . As the Ko concentration increases, dust enhances flow field instability, thereby accelerating the transformation of the flame structure. Meanwhile, higher hydrogen addition ( R ) intensifies chemiluminescence, and heated Ko particles to emit strong intense thermal radiation. The combined effect of these two factors causes the flame to appear bright white-yellow. A coupled analysis of flame propagation and pressure evolution reveals that, despite differences in φ , the coupled evolution of flame and pressure remains highly similar under the same R . The main distinctions arise in the timing of critical flame development stage and flame brightness. Overall, Ko suppresses explosions primarily through physical mechanisms such as endothermic cooling, dilution and isolation effects, and thermal radiation shielding, and it exhibits particularly strong suppression at high H 2 additions.
研究领域:
燃烧工程
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爆炸安全
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能源科学
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火灾与危害防护
✓ 已验证
产品关联
DOI
高影响因子
FUEL
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2021
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IF 6.609
Yaqi Wu,Danhua Yuan,Shu Zeng,Liping Yang,Xingzong Dong,Quan Zhang,Yunpeng Xu,Zhongmin Liu
Adsorption based process for CH 4 /N 2 separation is promising and attractive while it remains a challenge endeavor due to the lack of efficient adsorbents. In this work, amine ion-exchanged Y zeolites were developed for CH 4 /N 2 separation. By simple ion-exchanged with tetramethylammonium cation (TMA + ) and choline cation (Ch + ), CH 4 adsorption amounts of the resulting adsorbents were obviously increased while their N 2 adsorption amounts were significantly decreased. Consequently, CH 4 /N 2 separation performances of resulted samples were greatly improved compared to pristine NaY. CH 4 /N 2 selectivities of resulting sample TMAY and ChY were up to 6.32 and 6.50, respectively, at 25 °C and 100 kPa. Monte Carlo calculations were used to study the interaction affinity for CH 4 and N 2 on the adsorbents. Breakthrough experiments were further confirmed the excellent separation performances of TMAY and ChY. The excellent separation performances of the resulting adsorbents verified the efficiency of the simple ion-exchange strategy and the application potential of the adsorbents.
研究领域:
化学工程
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材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）