FUEL
·
2022
·
IF 8.035
Yueqing Wang,Hongxing Wang,Junbo Zhang,Hongyan Zheng,Long Huang,Yulei Zhu
Selectively converting fructose into furfural by H-beta catalyst is a very interesting catalytic process. However, it is a challenging task to clearly elucidate the roles of framework Al for selective scission of C C and C O bond. Herein, selective elimination of framework Al atoms is realized. Several detailed investigations showed that the framework Al species located in different sites play important role in furfural formation. The framework Al atoms of pristine H-beta mainly occupied at T1, T2, T5, T6 and T7 sites. These Al species at pore mouth can be removed by citric acid, while the treatment of nitric acid mainly eliminated the framework Al atoms from T2 and T7 sites. As for oxalic acid, the Al atoms occupied at T2, T5, T6 and T7 was primarily leached. Upon citric acid and nitric acid treatment afforded the similar yield of furfural, indicating that the formation of furfural could not be governed by these Al species at pore mouth, T2 and T7 sites. However, in the case of oxalic acid treatment, complete removal of the Al species on T2, T5, T6 and T7 sites decreased the yield of furfural. Thus, it is reasonably inferred that these Al atoms populated at T1 sites and intersecting channels is more encouraging for the splitting of C C bond, while the Al species occupied at T5, T6 sites and the larger straight channels is probably more favorable to scission of C O bond.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Xin Guo,Zhiyong Ding,Na Kang,Liu Yang,Yuanjiang Wang,Cheng Zhang,Zhaoqiang Li,Tiantian Zhang,Yan Wang,Yu Wang,Hao Qu
The zeolite-based catalyst is a promising option for the selective catalytic reduction (SCR) of nitrogen oxides (NO x ) due to its low toxicity. However, the challenge lies in its low-temperature activity. This study developed a multi-component catalytic system consisting of Ce/Mn/Cu-loaded Beta zeolite to reduce NO x . With fixed contents of Cu and Mn, we investigated the NH 3 -SCR process and the mechanism of action of the rare-earth species (i.e., Ce) in the system. Upon optimization of the content of Ce, the Ce/Mn/Cu-loaded Beta zeolite demonstrated enhanced low-temperature activity compared to samples loaded with Cu or Cu/Mn in the temperature range of 150–250 °C. When Ce was loaded in an appropriate proportion, it regulated the oxidation state of Cu, optimizing active adsorption species for NO and strengthening the strength of Brønsted acid sites in the catalyst. These synergetic effects led to improved NH 3 -SCR catalytic performance. This study can contribute to a better understanding of multiple metal-loaded zeolites in the NH 3 -SCR process and inform future design of Beta-type catalysts.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Xuan Tang,Ming Wang,Bingjing Tang,Yunkun Zhao,Wangcheng Zhan,Yanglong Guo,Li Wang,Sheng Dai,Yun Guo
Realizing the potential benefits of nanoscale metal catalysts requires highly dispersed active sites and control of their local environment. Herein, we develop a catalyst synthesis route for manipulating the local environment of highly dispersed metal-active sites via the targeted deposition of Pd near highly dispersed ZrOx on ZSM-5 zeolite using electrostatic interactions. The formed heteroatom Pd-ZrOx in zeolite catalysts is characterized by scanning transmission electron microscopy (STEM), in situ infrared spectroscopy, temperature-programmed desorption (TPD) of O2, and temperature-programmed surface reaction (TPSR) of CH4. The combination of diverse characterization results demonstrates the heteroatom Pd-ZrOx species rendering a higher dispersion and lower oxygen coordination of Pd species, appropriately tuning the strength of Pd–O bonds, and providing abundant active oxygen species to accelerate the dissociation of CH4. Therefore, the catalytic performance of Pd species is effectively enhanced with the lowest temperature of 90% CH4 conversion decreasing from 390 °C (without ZrOx) to 340 °C. Our work provides a strategy of engineering to anchor highly dispersed noble metal species and regulate the local environment to tune catalytic properties.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-10
·
IF 17.694
Yao Jie,He Yingluo,Zeng Yan,Feng Xiaobo,Fan Jiaqi,Komiyama Shoya,Yong Xiaojing,Zhang Wei,Zhao Tiejian,Guo Zhongshan,Peng Xiaobo,Yang Guohui,Tsubaki Noritatsu
Reduction process is a key step to fabricate metal-zeolite catalysts in catalytic synthesis. However, because of the strong interaction force, metal oxides in zeolites are very difficult to be reduced. Existing reduction technologies are always energy-intensive, and inevitably cause the agglomeration of metallic particles in metal-zeolite catalysts or destroy zeolite structure in severe cases. Herein, we disclose that zeolites after ion exchange of ammonium have an interesting and unexpected self-reducing feature. It can accurately control the reduction of metal-zeolite catalysts, via in situ ammonia production from ‘ammonia pools’, meanwhile, restrains the growth of the size of metals. Such new and reliable ammonia pool effect is not influenced by topological structures of zeolites, and works well on reducible metals. The ammonia pool effect is ultimately attributed to an atmosphere-confined self-regulation mechanism. This methodology will significantly promote the fabrication for metal-zeolite catalysts, and further facilitate design and development of low-cost and high-activity catalysts.
研究领域:
催化
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化学工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Shui Yang,Jialing Song,Yihua Yue,Bin Chen,Sajid Ali,Kok Bing Tan,Jian Tian,Jiale Huang,Qingbiao Li,Guowu Zhan
CO 2 hydrogenation to high-value-added light olefins over bifunctional catalysts is a promising pathway toward achieving net zero emissions. Herein, a series of SAPO-34 zeolites (bio-SAPO-34) with consistent acid properties but different particle sizes ( e.g. , 170 nm, 610 nm, and 7.50 μm) were synthesized using rice husk as the sole silicon source. Meanwhile, the rice husk derived SiO 2 (bio-SiO 2 ) could serve as a platform to assemble SAPO-34 and ZnZrO x into a bifunctional catalyst. It was found that the bio-SAPO-34 with the smaller particle size resulted in higher selectivity of light olefins and better long-term stability. Especially, after integration with ZnZrO x , the bio-SAPO-34 with a particle size of 170 nm exhibited higher light olefins selectivity (89.6 vs. 58.5 %) and longer catalytic lifetime (1000 vs. 59 min), as compared to a particle size of 26.0 μm. Notably, the zero length column (ZLC) technique, N 2 physisorption, and thermogravimetric analyses revealed that reducing the particle size of bio-SAPO-34 significantly decreases the diffusion resistance of light olefins in zeolites by shortening the diffusion paths, thereby inhibiting the formation of coke and enhancing the catalytic stability. Moreover, the bio-SiO 2 platform acts as a light olefins diffusion promoter by decreasing the surface diffusion resistance between zeolite particles and significantly alleviating the coke formation.
研究领域:
催化
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材料科学
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化学工程
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环境科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2016
·
IF 5.267
Lujiang Xu,Qian Yao,Zheng Han,Ying Zhang,Yao Fu
In this study, polylactic acid served as raw material to produce fine chemicals (pyridines) via a thermocatalytic conversion and ammonization (TCC-A) process. Ammonia was employed as not only carrier gas but also a reactant in this process. The thermal decomposition behavior of PLA under N2 or NH3 atmosphere was investigated. Different catalysts, including MCM-41, β-zeolite, ZSM-5 (Si/Al = 50) and HZSM-5 with different Si/Al ratios (Si/Al = 25, 50, 80) were also screened. Reaction temperature and residence time, which may affect the pyridines production, were investigated systematically. It was verified that all the investigated factors, including catalyst structure, catalyst acid amounts, reaction temperature, and residence time, influenced the PLA conversion and the pyridines production. The highest pyridines yield, 24.8%, was achieved by using HZSM-5 (Si/Al = 25) at around 500 °C. The catalyst regeneration tests were carried out. It demonstrated that the catalyst was stable after five regenerations and the catalytic activity did not change significantly. A possible reaction pathway from PLA to pyridines was also proposed. PLA initially thermally decomposed to form lactic acid and some byproducts such as acetaldehyde, acetone, etc., and then lactic acid, the mixture of acetaldehyde and acetone, or other byproducts reacted with ammonia to form imines and finally underwent complicated reactions to form pyridines.
研究领域:
化学工程
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环境科学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2025
·Vol. 15
·期 5
·321
·
IF 4.3
Boyang Xu,Jie Chen,Kai Wang,Pengfei Li,Le Kang,Huiling Du,Qianqian Liu,Xiaoqing Lian
The accumulation of organic pollutants and solid waste is one of the major environmental challenges faced globally. Establishing an efficient recycling system for solid waste and designing cost-effective, high-performance photocatalysts are urgent tasks for the removal of organic pollutants from water. This study utilizes coal gangue as the precursor to synthesize a coal gangue-based phosphorus–silicon–aluminum molecular sieve (SAPO-5) via hydrothermal synthesis. The resulting material was then composited with bismuth oxybromide (BiOBr) to form a novel BiOBr/coal gangue-based SAPO-5 nanocomposite. When the mass ratio of BiOBr to coal gangue-based SAPO-5 molecular sieve is 0.3, the synthesized nanocomposite exhibits excellent adsorption and photocatalytic performance for the removal of methylene blue, achieving a removal rate of 97.8% and the mineralization rate of 57.4% within 30 min. The superior performance can be attributed to the optimal pore size, rapid charge transfer rate, and high photogenerated charge density of the BiOBr/coal gangue-based SAPO-5 nanocomposite. The novel BiOBr/coal gangue-based SAPO-5 molecular sieve nanocomposite catalyst presents a new approach for the harmless treatment of organic dye wastewater and the high-value utilization of coal gangue.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Jingjing Wang,Jinchuan Zhao,Zhihui Wen,Xinjie Wei,Junjie Liao,Liping Chang,Kechang Xie
CeY zeolite sorbent was reported to have a high adsorptive desulfurization selectivity for thiophene. However, only the cerium in the supercage, which is larger than the thiophene molecule, is effective for thiophene adsorption. In this case, regulating the cerium location to anchor it more in the surpercage of Y zeolite is an important issue. Herein, the glycine was used as a complexing agent with cerium to control its size, ensuring that the cerium precursor is in the supercage. G 0.1 CeY were prepared by ion exchange technique with glycine and cerium coordination from NaY. The adsorption capacity of sorbents was measured, and their physical and chemical properties were characterized by XRD, SEM, N 2 adsorption/desorption, NH 3 -TPD, and in situ FT − IR. The glycine complexation could effectively control the location of Ce, so that the G 0.1 CeY has the highest content of Ce located in the supercage. Moreover, in order to further explore the influence of zeolite type, HY was used as the raw material to prepared G 0.1 CeHY in the same way. G 0.1 CeHY has a higher desulfurization performance than that of G 0.1 CeY, whereas the Ce content in its supercage is lower. The NH 3 -TPD and Py-FT − IR results that the medium-strong Brønsted acid of the G 0.1 CeHY sorbent is also effectively for the improvement of desulfurization efficiency. The G 0.1 CeHY exhibits the hightest desulfurization effectiveness (51 %) and the highest breakthrough adsorption capacity of 5.42 mg/g.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 22
·5251
·
IF 4.2
Yangyang Xie,Honglei Fan,Mingyang Che,Ya Liu,Chunjing Liu,Xin Hu,Botao Teng
Adsorbing and recycling alcohols and acids from industrial wastewater is of great significance in wastewater treatment; establishing the possible quantitative relationship of alcohol–acid adsorption capacity with the struct0ures of adsorbents and exploring the key factors determining their adsorption performance is very important and challenging in environment science. To solve this difficult problem, the adsorption of C1-5 alcohols, C2-4 acids, and Fischer–Tropsch synthesis (FTS) wastewater on zeolites with similar hydrophobicity and pore structures (β and MFI), similar hydrophilicity but different pore structures (Y and MOR), and similar pore structures but significant differences in hydrophobicity (MOR vs. β and MFI) was systematically investigated. It was found that: (1) For materials with similar pore structures, increased hydrophobicity correlates with enhanced adsorption capacities for alcohols and acids. (2) For materials with similar hydrophobicity, a higher content of ultramicropores leads to increased adsorption of alcohols and acids. (3) Between pore structure and hydrophobicity, it is hydrophobicity that ultimately plays a decisive role in adsorption capacities. The adsorption behavior of zeolites in FTS wastewater exhibits a consistent trend, with β-zeolite demonstrating the highest hydrophobicity (contact angle of 105°) and the greatest adsorption capacity in FTS wastewater, achieving 103 mg/g. Following five adsorption–desorption cycles, the zeolites retained their adsorption capacity without significant degradation, indicating their excellent stability and reusability. The findings identify the critical factors determining adsorption performance and provide a solid foundation for the design and development of high-performance adsorbents for alcohol–acid adsorption.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 3
·698-712
·
IF 2.482
Yu Shanqing,Yan Jiasong,Lin Wei,Long Jun,Liu Shang-Bin
Abstract A better understanding of the roles of rare earth (RE) in heterogeneous catalysts is crucial for improving the properties of catalysts in petro-chemical industry. Fluid catalytic cracking (FCC) catalysts containing RE-incorporated Y zeolites with excellent stability and activity are continuously used to improve the conversion of heavy oil into transportation fuels. In this paper, the effect mechanism of Lanthanum (La) on stability and acidity of Y zeolites are elucidated in conjunction with their influences on catalytic performance. The improvement on stability of La-incorporated Y zeolites can be attributed to the La incorporation which bonds strongly with framework O2 and O3 atoms and strengthens the interaction between framework Al and its neighbouring O atoms. It is the enhanced stability restrains the release of framework Al and the formation of extra-framework Al, hence leads to a decrease of total L acid amount and an increase of total B acid amount, especially a clear increase in medium strength B acid amount (with 31 P NMR/TMPO chemical shifts at 62 and 58) and a significant decrease in strong B acid amount (with 31 P NMR/TMPO chemical shifts at 70 and 65) with the incorporation of La into Y zeolites. However, the total acid amount decreases significantly when La 2 O 3 content is high. The increase of B acid amount and improved stability of LaHY zeolites, boost the conversion ability and isomerization ability of heavy oil, while resulting in poor olefins selectivity and coke selectivity caused by the enhancement of hydrogen transfer reactions. Therefore, Y zeolite containing appropriate La 2 O 3 content should be considered to enhance heavy oil cracking ability while boosting light olefins production and optimizing coke selectivity. Graphic Abstract
研究领域:
石油化工
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Qing Dai,Wenjing Lu,Yuyue Zhao,Huamin Zhang,Xiangxue Zhu,Xianfeng Li
A zeolite composite membrane (ZCM) was designed and fabricated via a simple versatile and scalable method. A thin layer of ZSM-35 flakes with pore size between hydrated protons and vanadium ions was fixed on the poly(ether-sulfone)/sulfonated poly(ether-ether-ketone) (PES/SPEEK) porous substrate by in-situ interfacial polymerization. The ZSM flake layer can perfectly separate hydrated vanadium ions and protons, therefore, show very impressive performance for vanadium flow batteries (VFBs). As a result, a VFB assembled with an optimized ZCM exhibited a columbic efficiency more than 99% and energy efficiency of over 91% at a current density of 80 mA cm -2 , which is among the highest performance ever reported. Furthermore, the energy efficiency can reach 81.6% at a very high current density of 200 mA cm -2 and keep stable for 1000 cycles at a current density of 180 mA cm -2 . This method opened a door toward the large-scale production of highly selective composite membranes for flow batteries.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 6
·948
·
IF 3.9
Rui Hu,Tianye Wang,Yifan Wang,Yuan Zhu,Li Xie,Enhui Xing,Yu Wu,Zhijian Da
A nano-hollow zeolite-encapsulating ultra-fine Fe nanoparticle catalyst denoted as Fe@n-hS-HT was successfully synthesized through a simple water steam treatment of the Fe@n-hS catalyst prepared by the “dissolution–recrystallization” (D-R) method. The Fe@n-hS-HT catalyst had a hierarchical porous structure and a high dispersion of Fe2O3particles with a size of 3.4 nm. Furthermore, the results of several characterization methods, such as XRD, HAADF-STEM, and H2-TPR, further demonstrated the transformation of the skeleton Fe in Fe@n-hS into Fe2O3, which was uniformly dispersed in the Fe@n-hS-HT catalyst. Meanwhile, Fe@n-hS-HT had significantly higher selectivity and yield of C2-C4=than the reference catalysts Fe/S and Fe@n-hS, which provided strong proof for the confined catalysis of the metal@zeolite catalyst.Keywords:hollow zeolite;Fischer–Tropsch synthesis;encapsulation;iron catalyst
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
危险品化学品经营许可证（带存储）