APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Weiyuan Yao,Yue Liu,Zhongbiao Wu
A series of CeO 2 @Ce-O-P “multi-core@shell” catalysts were synthesized in this paper for selective catalytic reduction (SCR) of NO with NH 3 . The experimental results had showed that CeO 2 @Ce-O-P-30:3 yielded best SO 2 tolerance of an over 70% deNO x efficiency at 250 °C in the presence of 100 ppm SO 2 for 20 h, which was much higher compared to pure Ce-O-P and CeO 2 samples. Further characterization results indicated that Ce-O-P coating layer could somewhat inhibit sulfur depositing on the catalysts during SCR reaction in the presence of SO 2 , thereby protecting the active sites from SO 2 poisoning. Especially, O 2 -TPD results illustrated that a great amount of active oxygen species were retained on used CeO 2 @Ce-O-P catalyst after a long term reaction. The synergetic effect of “multi-core@shell” structure could be attributed to such enhanced performances. The “core” CeO 2 devoted abundant active oxygen sites to fulfill the SCR reaction. And the “shell” Ce-O-P could not only provide acid sites, but also protect the active oxygen species by avoiding the over-adsorption of SO 2 on the catalyst. This work could provide a new way to increase the sulfur resistance for low temperature SCR catalysts.
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
Plasma Processes and Polymers
·
2023
·Vol. 20
·期 5
·2200228
·
IF 3.5
Siyuan Sui,Hongmei Sun,Guohua Ni,Yafeng Liu,Huan Zheng,Tao Sun,Ling Kong,Zhongyang Ma,Fangli Yuan
The surface of polytetrafluoroethylene (PTFE) is activated by argon (Ar), Ar mixed with water vapor (Ar-H 2 O), and a mixture of Ar, water vapor, and ammonia (Ar-H 2 O-NH 3 ) plasmas and then grafted onto polymerized dopamine/ethylene imine and immobilized heparin. Oxygen-containing functional groups are all introduced onto the PTFE surface treated by three types of plasma. The amount of oxygen grafted is the highest in samples treated with Ar-H 2 O-NH 3 plasma compared to that treated with Ar-H 2 O plasma. An increase in the content of oxygen grafted onto PTFE contributes to an increase in the thickness and cross-linking bond of the polymeric interlayer and then raises the density of the heparin coating. The thickness of the polydopamine/polyethylenimide intermediate layer on the surface of PTFE treated with Ar-H 2 O-NH 3 plasma is 4.8 ± 0.3 μm, and the density of the immobilized heparin coating was 95 μg/cm 2 .
研究领域:
材料科学
·
表面化学
·
生物医学工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Quanhua Wang,Wenwen Zhang,Xiaosen Ma,Yanchao Liu,Lichen Zhang,Jiajun Zheng,Yan Wang,Wenlin Li,Binbin Fan,Ruifeng Li
Hierarchical SAPO-34 zeolites with tunable porosity were hydrothermally synthesized by modulating the Si/Al molar ratios of the gel precursors, and the morphologies of SAPO-34 crystals gradually evolve from well-dispersed ultra-small nanocrystals to compactly polycrystalline aggregates, and to analogous polycrystallinites but adhered with minute amorphous debris by increasing the Si/Al ratio ranging from 0.20 to 0.67. The catalytic tests during methanol-to-olefins (MTO) reaction indicate that the Hier-SAPO-34-0.20 (Si/Al = 0.20) catalyst constructed by loosely nano-sized crystals centered at 50 nm presents prominent catalytic performances with about 2.5 times prolonged catalytic longevity and around 10 % improvement for the selectivity toward light olefins (ethylene and propylene) as compared to a reference catalyst. More interestingly, when Hier-SAPO-34-0.20 catalyst was in situ pretreated with NH 3 flowing, the selectivity of light olefins can be greatly increased by 18.1 % at the initial stage and the corresponding even selectivity with time-on-stream can be elevated by 6.9 %. It founds that in situ NH 3 -poisoned catalysts with improved light olefins selectivity are also suitable for ZSM-5 zeolite. These results reveal that the weakened strong acid sites modified by NH 3 -poisoning play a pivotal role in suppressing the undesired hydrogen transfer reactions and thus giving a high selectivity for light olefins. This work highlights the importance of acidity fine-tailoring by in-situ NH 3 -poisoning strategy on hierarchical zeolites for the improvement of light olefin selectivity, which would be valuable guidance for industrial applications.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Peng Sun,Rui-tang Guo,Shu-ming Liu,Shu-xian Wang,Wei-guo Pan,Ming-yuan Li,Shuai-wei Liu,Jian Liu,Xiao Sun
CeSmOx mixed oxide catalysts supported on TiO 2 prepared by coprecipitation method were used for selective catalytic reduction of NOx with NH 3 . The results showed that the addition of Sm could effectively enhance the low-temperature SCR activity and SO 2 /H 2 O resistance of Ce/TiO 2 catalyst, and the appropriate mole ratio of Sm to Ce was 0.3. Characterization results indicated that the introduction of Sm could promote the formation of Ce 3+ and chemisorbed oxygen species on catalyst surface, which was favorable to the generation of NO 2 . Moreover, the doping of Sm could also promote the adsorption of NH 3 and NOx species on Ce/TiO 2 catalyst. The results of in situ DRIFT study revealed that the NH 3 -SCR reaction over CeSm/TiO 2 -0.3 catalyst was mainly controlled by the Langmuir−Hinshelwood mechanism in the low temperature range (<200 °C). Thereafter, the promoted NO oxidation and the enhanced NH 3 adsorption should play a major role for the excellent low-temperature SCR performance of CeSm/TiO 2 -0.3 catalyst.
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Yu Zhang,Rui Wang
NH 3 ‑selective catalytic reduction as the fascinating technology for complete NO x removal, the key in practical applications is to explore advanced catalysts with high catalytic reactivity and stability at low temperature. Herein, a series of hollow spherical AMnO x (A = Ce, Cu, Ni) catalysts was fabricated by using carbon nanospheres as sacrificial template. Characterization analysis including XRD, ICP, BET, SEM, TEM, H 2 -TPR, NH 3 -TPD, XPS, in situ DRIFTS together with kinetic studies were applied to acquire knowledge of the morphological structure and surface features of the catalysts as-prepared. We also performed a comparative study on three samples with regard to their SCR activity at low temperatures. Notable, the catalytic activity of the NiMnO x catalyst (95.9 %) was vastly superior to that of the CeMnO x (85.4 %) and CuMnO x (30.5 %) at 100 °C. This enhanced low-temperature activity of NiMnO x are correlated against hollow structure with more active sites, wider pore distribution, higher surface Mn content and the enhancement in surface acidity and reducibility. Even with 5 vol% H 2 O in the reaction gas fraction, the catalytic performance of NiMnO x hollow spheres was superior to the other two catalysts. Besides, it can be used for six consecutive runs without suffering a substantial activity loss. Additionally, the impact of various crucial process variables, including space velocity, H 2 O, SO 2 , and metal poisons, on the denitrification efficiency of NH 3 -SCR was examined. The current researches have a positive guiding role in the development of high-efficiency low-temperature NH 3 -SCR denitrification catalysts to boost NO x degradation.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Qin Wu,Chi Fan,Ya Wang,Xiaoping Chen,Guimin Wang,Zhengxing Qin,Svetlana Mintova,Junhua Li,Jianjun Chen
The reduction of NO x emission during the cold start period of diesel vehicles requires special attention in accordance with the emission regulations. In this work, the direct incorporation of cerium and copper in SAPO-18 catalyst with AEI type framework structure (CuCe-SAPO-18) resulting in a substantial enhancement of the performance in the low-temperature NH 3 -SCR reaction (<200 ℃). A small amount of cerium (0.13–0.31 wt%) broadened the reaction temperature range of use and increased the hydrothermal stability of the catalyst considerably. The cerium species was introduced in the ion-exchange sites of Cu-SAPO-18 in the form of Ce 3+ ions even with high loading (3.15 wt%). The Ce 3+ ions were found to affect the distribution of silicon and aluminum atom coordination ( 29 Si NMR, 27 Al MAS NMR) in the AEI-type skeleton structure leading to an increase of both the amount of active Cu 2+ species and the acidity of the CuCe-SAPO-18 catalysts that are beneficial for the NH 3 -SCR reaction.
研究领域:
催化化学
·
环境科学
·
材料化学
·
大气污染控制
·
无机固体化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Fanzhi Meng,Tongyao Ju,Siyu Han,Li Lin,Jinglin Li,Kailun Chen,Jianguo Jiang
The biphasic amine solvent based on ionic liquid could effectively improve the efficiency of carbon dioxide capture and regeneration, greatly reduce the energy consumption of regeneration, and hold an excellent application prospect in the field of large-scale biogas upgrading. In this work, a biphasic mixed amine system consisting of Methyl monoethanolamine (MMEA), N-methyldiethanolamine (MDEA), and 1-butyl-3-methylimidazolium tetrafluoroborate (BF) was prepared for the removal of trace components and CO 2 during biogas upgrading and compared with traditional 30 wt% MEA and mixed amine solution of MMEA and MDEA for biogas upgrading. The results showed that H 2 S and NH 3 would chemically react with the biphasic solvent and thus facilitate the removal of trace components, and that the reacted solution would not affect its regeneration characteristics and could basically be recycled at a regeneration temperature of 125 °C. In addition, the phase separation efficiency of the biphasic agent was not affected by the introduction of trace components, and all reaction products except the ionic liquid were enriched in the rich phases and the carbon enrichment rate reached about 98%, which reduced regeneration energy consumption by 44.07% compared to 30 wt% MEA. Finally, the mechanism of phase separation of reaction products and ionic liquids was discussed in the context of quantum chemical calculations, and the importance of intermolecular van der Waals forces in the phase separation process was clarified, and the reasons for the appearance of phase separation phenomena were explained.
研究领域:
化学工程
·
环境科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Changfan Xu,Huanwei Wang,Jing Zhan,Yao Kang,Feng Liang
Designing catalytic cathodes with excellent electrocatalytic activities and durability for Na-CO 2 batteries has captured considerable attention so far. Here, a series of morphologically controlled low-crystalline CuCo 2 O 4 was prepared by thermal oxidation of self-assembled Cu-Co precursors ( p -CCO). One-dimensional (1D) rod-like of CuCo 2 O 4 was subsequently encapsulated in polypyrrole shell (PPy) by in-situ polymerization of pyrrole monomers as an advanced catalyst (CCO/PPy) for high-performance Na-CO 2 batteries . It was demonstrated that ammonia solution exerts an important influence on the surface morphology and size of the p -CCO crystallites by the rate of nucleation and growth. Particle size and 1D architecture modulation, associated with the encapsulation of conductive PPy effectively improve the directional transfer rate of ions and the conductivity of the electrode. More importantly, PPy introduction not only induces interfacial reconstruction of CuCo 2 O 4 , arousing more oxygen vacancies and catalytic active sites, but also contributes to the corrosion protection of the active material from the electrolyte during long-term operation. Bestowed by these advantages, the fabricated hybrid Na-CO 2 battery manifested prominent electrochemical performance with a superior areal discharge capacity of 31.3 mAh cm −2 , low discharge-charge voltage gap of 0.6 V, over 400 cycles.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
Sustainable Materials and Technologies
·
2024
·
IF 8.6
Lei Guo,Yan-He Chen,Li-Mei Xu,Xiao-Lu Chen,Jin-Qiu Shen,Jian-Yong Zhang,Zhen-Jiang Liu
Herein, a fern-like p-n heterojunction by anchoring Ni 3 Fe-LDH nanoplates onto Co 3 O 4 nanoneedles have been optionally constructed. Essentially, p-n heterojunction ensured to induce strong built-in electric field, and inherit interfacial electron redistribution. Based on their compatible and well-matched electronic band structures, a staggered type-II photo-generated electron/holes transfer pathway have been elaborated by density functional theory calculation (DFT), in situ irradiation X-ray photoelectron spectroscopy (XPS), and fluorescent decay. This band bending and charge migrating module conferred the architecture with strong redox ability, sufficient exciton dissociation, and admirable optoelectronic characteristics. Moreover, the heterostructure acquired broad absorption spectrum to exhibit outperforming photocatalytic effect. Totally, this electron redistribution at the hierarchical interface, a type-II scheme charge-transfer pathway and the oxygen defects would lead to high efficiency in solar light assisted N 2 reduction. Typically, Co@Ni 3 Fe-2 catalyst exhibited the highest NH 3 production rate of 16.15 μg h −1 mg cat. −1 and Faraday efficiency (FE) of 31.57% at −0.6 V vs. RHE in 0.1 M Na 2 SO 4 solution. Fortunately, with light exposure, the NH 3 production rate and FE could increase by 27.9% and 18.1% than that under dark. This work would provide a plausible attitude towards the design of high efficient photocatalyst for artificial photosynthesis with multi-functionalized coupling effect.
研究领域:
材料科学
·
催化
·
光化学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2023
·Vol. 10
·期 19
·5700-5709
·
IF 7
Yixian Liu,Ruqiang Wu,Yunliang Liu,Peiji Deng,Yaxi Li,Yuanyuan Cheng,Yongchao Du,Zenan Li,Xiong Yan,Naiyun Liu,Zhenhui Kang,Haitao Li
As an environmentally friendly and sustainable method for ammonia synthesis, nitrogen reduction reaction (NRR) by electrocatalysis possesses several advantages, including viability under mild conditions, abundant reaction raw materials and low energy consumption, and thus it is supposed to be a promising alternative to the traditional Haber–Bosch process. However, the stable NN bonds in the nitrogen (N2) and the competing hydrogen evolution reaction (HER) put harsh requirements on catalysts. In this study, the CoS/MoS2 heterojunction catalyst where CoS nanoparticles are anchored on the MoS2 nanosheets is reported as a high-efficiency NRR catalyst. The catalysts have high NH3 yield (23.23 μg h−1 mgcat.−1), reasonable faradaic efficiency (FE, 12.63%) and long-term electrochemical stability under −0.45 V vs. RHE in 0.1 M Na2SO4 solution, whose performance is better than MoS2 and CoS. The TPV results show rapid interfacial electron transfer and good conductivity of the material, and the DFT calculation reveals that the CoS attached to the (100) plane effectively enhances N2 adsorption and catalysis performance.
研究领域:
材料科学
·
电化学
·
催化
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2018
·
IF 4.521
Xiaoqiang Wang,Yue Liu,Qingji Ying,Weiyuan Yao,Zhongbiao Wu
In this paper, a series of Nb modified Cu-Ce-Ti mixed oxides (Nb y CCT) were synthesized using wetness impregnation method for the selective catalytic reduction of NO with ammonia (NH 3 -SCR). The activity tests indicated that Nb y CCT catalysts had shown superior SCR performances. Among which, Nb 0.05 CCT catalyst exhibited a NO conversion of more than 90% within a broad operation temperature window (180–360 °C) under the GHSV of 40,000 h −1 . After that, corresponding characterizations were performed to correlate the physical structures and surface properties to catalytic performances. These results revealed that the strong interactions among the active phases induced by Nb addition could not only enhance the redox property of the catalysts but also inhibit the over-oxidation of NH 3 , which would be beneficial to SCR performance within a wide temperature range and good reaction selectivity. Furthermore, DRIFTS results suggested that the doping of Nb could promote the formation of NO 2 , thereby enhancing the “fast” SCR reaction process (Langmuir-Hinshelwood reaction pathway). Moreover, the Nb 0.05 CCT catalyst showed a better sulfur tolerance compared to Nb free catalyst that over 85% NO conversion could be retained after 12 h SCR reaction in the presence of SO 2 and H 2 O.
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Xin Yang,Kaijie Liu,Xinyu Han,Jianheng Xu,Mengyao Bian,Daying Zheng,Haijiao Xie,Yibo Zhang,Xiangguang Yang
It is essential to develop the catalyst for NH 3 -SCR with excellent performance at ultra-low temperature (≤150 °C), and resource recycling is another important part of environmental protection. Based on the principle of environmental friendliness, the LiMn 2 O 4 , one of the waste battery cathode materials, was successfully modified into a novel high-value catalyst for ultra-low temperature NH 3 -SCR through hydrogen ion exchange and two-dimensional vanadic oxide modification. The optimized LiMn 2 O 4 -0.5V-10H catalyst performed the best balance of NO x conversion and N 2 selectivity , with activity reaching 96 % at 150 °C and N 2 selectivity exceeding 70 % at ultra-low temperature. Due to the unique three-dimensional network structural characteristics of LiMn 2 O 4 spinel, hydrogen exchange could exchange Li + from the lattice and increase surface acidity; and a small amount of two-dimensional vanadic oxide loading could appropriately regulate redox ability and increase acidic sites. The in-situ DRIFTS results still showed that the L-H and E-R mechanisms coexisted during the reaction. Moreover, combining first-principles calculations and in-situ DRIFTS, the dual modification of H and V could enhance the adsorption of NH 3 on the surface of LiMn 2 O 4 but weaken the adsorption of NO, and promote the decomposition of nitrites while inhibit the formation of surface nitrate species, which was the core reason for the improvement of N 2 selectivity. The modification mode in this work was simple and inexpensive, which provided a new idea for the high-value utilization of waste batteries and the design of NO x purification catalyst at ultra-low temperature.
研究领域:
环境科学
·
催化
·
材料科学
·
化学工程
✓ 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）