CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yuhong Tao,Chengqi Feng,Juncheng Huang,Haining Na,Jin Zhu
Phosphotungstic acid hydrate (HPW)-doped hydroxyl-rich hydrothermal carbon-coated fibrous silica catalyst (FS@C/HPW) is fabricated to induce the highly efficient hydrolysis of cellulose to sugar in an ultra-low acid aqueous system. The obtained FS90@C/HPW12 owns good thermal stability under 200 °C and the highest specific surface area at 28 m 2 /g. Owing to its special fibrous microstructures, FS90@C/HPW12 can cause linear damage and structural fragmentation on the surface of cellulose during hydrolysis. Accordingly, rather highly efficient hydrolysis with the cellulose conversion of 100 %, total reducing sugar and glucose yields at 92.2 % and over 85 % is achieved in the aqueous system with FS90@C/HPW12 and 5 mmol/L H 2 SO 4 . FS90@C/HPW12 also exhibits good reusability in multiple hydrolysis. This research provides a particular way for the design and synthesis of solid catalysts to induce the highly efficient hydrolysis of cellulose to sugar by chemical catalysis in a full aqueous system.
研究领域:
生物化学
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材料科学
✓ 已验证
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Ze Zhang,Jun Cheng,Yanxia Zhu,Hao Guo,Weijuan Yang
To promote hydrocracking and isomerization activities of bifunctional catalyst for the conversion of methyl palmitate into jet biofuel, phosphotungstic acid (HPW) loaded on Ni/MCM-41 catalyst enhanced strong acidity to strengthen conversion pathways of hydrocracking and isomerization. In the bifunctional catalytic system, Ni catalyzed hydrodeoxygenation and dehydrogenation of methyl palmitate to produce 1-pentadecene, while acid sites catalyzed further conversion of 1-pentadecene to produce jet fuel range hydrocarbons. Quantum chemistry calculation showed that activation energy in chemisorption process of 1-pentadecene onto acid sites significantly reduced from 203.9 kJ/mol with MCM-41 to 81.6 kJ/mol with HPW. Since bond order of β-scission site in 1-pentadecene over HPW was 0.93% lower than that over MCM-41, and Hirshfeld atomic charge of carbenium ion in 1-pentadecene over HPW (0.0722) was much higher than that over MCM-41 (0.0473), HPW showed better catalytic activities than MCM-41 in both hydrocracking and isomerization processes. The overall selectivity of jet biofuel increased to 86.1% with 47.1% n-alkane selectivity and 8.3% iso-alkane selectivity, due to improved strong acid density from 0.563 to 0.730 mmol/g over 20% HPW-Ni/MCM-41 catalyst.
研究领域:
催化化学
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能源科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2020
·Vol. 58
·期 18
·2625-2633
·
IF 0
Shaojian He,Wenxu Dai,Shaoxiong Zhai,Hao Song,Jun Lin
In this work, we prepared amino-modified halloysite nanotubes (PEI-DHNTs) via the co-deposition of self-polymerized dopamine and polyethylenimine (PEI) on the surface of nanotubes, which was confirmed by X-ray photoelectron spectroscopy (XPS) and Thermogravimetric analysis (TGA). A series of composite proton exchange membranes (PEMs) were prepared by incorporating PEI-DHNTs and phosphotungstic acid (HPW) into sulfonated poly(ether ether ketone) (SPEEK). It was found that both PEI-DHNTs and HPW were well dispersed in the polymer matrix, exhibiting excellent filler-matrix compatibility. The composite membranes demonstrated enhanced proton conductivity, reaching as high as 0.078 S cm −1 with 33.3 wt.% HPW loading, which was ~90% higher than that of SPEEK control membrane. Such improvement was mainly attributed to the strong acid–base pairs formed by PEI-DHNT with both SPEEK and HPW, which shortened proton hopping distance and created more continuous proton conduction pathways. Furthermore, the membrane conductivity remained almost constant after 1 year's immersion in liquid water, indicating the successful immobilization of HPW in the composite membranes. Graphical Amino-modified halloysite nanotubes (PEI-DHNTs) were prepared and used to successfully immobilize phosphotungstic acid (HPW) in sulfonated poly(ether ether ketone) (SPEEK) composite membranes. Due to the strong acid-base pairing between PEI-DHNTs and SPEEK/HPW, the shorter proton-hopping distance and more continuous proton conduction pathways result in as high as ~90% improvement in proton conductivity for the composite membranes. Furthermore, the membrane conductivity remain almost constant after 1 year's immersion in liquid water.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2013
·Vol. 2013
·期 31
·5428-5435
·
IF 3.12
Shi Li,Shang-Ru Zhai,Jian-Ming Zhang,Zuo-Yi Xiao,Qing-Da An,Ming-Hui Li,Xiao-Wei Song
Graphical A novel, magnetically recoverable, and stable catalyst, Fe 3 O 4 @SiO 2 –NH 2 /HPW@CS/HPW, has been prepared and a high methyl oleate yield of 93.2 % was achieved in the esterification of methanol and oleic acid. A magnetically retrievable and stable composite, Fe 3 O 4 @SiO 2 –NH 2 /HPW@CS/HPW, in which H 3 PW 12 O 40 (abbreviated as HPW hereafter) was successfully anchored onto the surface of a cross-linked chitosan coating on magnetic Fe 3 O 4 cores, has been prepared by means of chemical bonding between the amino and HPW components. The resultant composites were characterized by different physicochemical techniques, such as TEM, SEM, FTIR, and vibrating sample magnetometry (VSM). An improved synthesis of methyl oleate from oleic acid and methanol was observed with the as-prepared material as catalyst with easy recovery by simply using an external magnet. A yield of 93.2 % of methyl oleate was achieved under the optimal reaction conditions, that is, a 20:1 molar ratio of methanol to oleic acid and 0.4 g catalyst at 60 °C for 4 h. It was demonstrated that improved catalytic performance and facilitated separation were simultaneously achieved in the esterification reactions as a result of the core@shell structures in which stabilized HPW and magnetic cores are integrated into one body.
研究领域:
材料科学
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催化
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纳米技术
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Meng-Long Liu,Tao Zhou,Xu Han,Yan-Hong Shen,Ying-Yu Song,Yong Wu,Ying Gao,Wen-Wen He
High-temperature proton exchange membrane fuel cells (HT-PEMFCs) usually show some obvious advantages like higher energy efficiency, cheaper hydrogen purification cost and simpler heat/water management systems. Design and synthesis of high-performance high-temperature proton exchange membranes (HT-PEMs) with excellent proton conductivity meanwhile enhanced mechanical properties still remain a huge challenge in HT-PEMFCs field. Herein, we designed and prepared a new proton conductor HPW@MOF-808. Subsequently, HPW@MOF-808 has been doped into poly(terphenyl piperidine) (PTP) polymer and some exceptionally well HT-PEMs have been prepared. Thanks to the transformation from zirconium-oxygen clusters of MOF-808 to ZrP 2 O 7 , the composite membranes show higher proton conduction and greater tensile strength. The PTP-2PM has a peak power density of 861.5 mW cm -2 , making it a promising candidate for HT-PEMFCs. Theoretical calculations demonstrate that ZrP 2 O 7 has stronger hydrogen bonds interactions with the main chain, leading to a denser hydrogen bonding network within the membrane and can effectively limit the separation of the membrane backbone. Moreover, the regular arrangement of HPW help to construct an additional proton transfer channel. In this work, a novel inorganic filler for HT-PEMs is proposed, it offers a fresh approach to developing high-performance HT-PEMs.
研究领域:
材料科学
·
能源工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2014
·Vol. 38
·期 8
·3999-4006
·
IF 3.159
Zhenzhen Wang,Shangru Zhai,Bin Zhai,Zuoyi Xiao,Feng Zhang,Qingda An
Novel protocol towards multifunctional magnetic organic–inorganic core–shell nanostructured catalysts of Fe3O4@SN/HPW@CG–Ag with tailored properties are presented in this work. Such nanocomposites congregate the properties and functions of a single component into a whole. For instance, Fe3O4 cores protected by amino-functionalized SiO2 shell endowed the composites with superparamagnetism (28.6 emu g−1) and thereby facilitate the process of separation and recovery. Phosphotungstic acid, as a bridging agent, provided a strong interaction for the anchoring of glutaraldehyde cross-linked chitosan onto the surface of Fe3O4@SN. More interestingly, chitosan could simultaneously behave as a stabilizer and reductant for the in situ synthesis of “green” Ag NPs without addition of any other reducing agent or organic solvent, and Ag NPs provided the compounds with a catalytic performance. Further the size, loading of Ag NPs and the thickness of the chitosan layer were all controllable. Meaningfully, the as-synthesized catalyst Fe3O4@SN/HPW@CG–Ag exhibited an exceptional catalytic performance for the reduction of 4-nitrophenol in the presence of sodium borohydride (the reaction was accomplished within 7 min) and could be reused at least 10 times with good stability by means of convenient magnetic separation. Thence, the design philosophy of the multifunctional robust Ag-based nanocatalysts may pave the way for the synthesis of other catalyst systems with long-term stability.
研究领域:
材料科学
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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
HIGH PERFORMANCE POLYMERS
·
2020
·
IF 1.568
Yingfeng Wang,Jiabin You,Zhuowei Cheng,Kun Jiang,Linlin Zhang,Wanli Cai,Yun-Quan Liu,Shuirong Li
An improved sulfonated poly (ether ether ketone) (SPEEK) nanocomposite membrane was prepared by incorporating both phosphotungstic acid (HPW) and Al doped cerium-based oxides (Al-CeZrO4) in SPEEK matrix. The HPW was immobilized by Al-CeZrO4 so that firmly dispersed acid–base pairs were formed. The introduction of Al-CeZrO4 helped improve the chemical stability of the pristine (baseline) SPEEK membrane without compromising the conductivity, and the addition of HPW further enhanced the conduction of protons through acid–base interactions. Stability tests showed that when the SPEEK/Al-CeZrO4 nanocomposite membrane was immersed in a Fenton’s solution for 108 h at 80°C, a loss of 34.9% in proton conductivity was observed, which is 24.1% less than that of the pristine SPEEK membrane, indicating that the attenuation of membrane proton conductivity was inhibited. At the same time, the proton conductivity of the SPEEK/Al-CeZrO4/HPW nanocomposite membrane (that has already incorporated HPW) was increased by 15.5% compared to the SPEEK/Al-CeZrO4 nanocomposite membrane. Hence, Al-CeZrO4/HPW is considered as an effective inorganic nanofiller for improving both proton conductivity and chemical stability of SPEEK membranes, and the hybrid composite membrane is worth further studying.
研究领域:
材料科学
·
燃料电池技术
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Peng Wei,Dong Huang,Yang Sui,Xi Li,Qingkun Liu,Bensheng Zhu,Chuanbo Cong,Pengpeng Bai,Yu Tian,Qiong Zhou,Xiaoyu Meng
Solid heteropolyacids with high intrinsic proton conductivity , like phosphotungstic acid (HPW), were added to further enhance the proton conductivity of sulfonated poly ether ketone (SPEEK). The great solubility of solid acid within water, however, would produce a dramatic decline in stability and durability. In this study, we utilized polydopamine (PDA) coated polyimide (PI) nanofiber to form the acid-base pair between PDA@PI nanofiber and HPW/SPEEK to anchor the HPW. Additionally, a pocket was constructed in the sandwich-structure PDA@PI/SPEEK + HPW membrane to help better anchor the HPW. After 6 weeks of durability treatment during 60 °C and 100% RH, proton conductivity of PDA@PI/SPEEK + HPW-20 was 163.5 mS cm −1 , which was only 23.0% lower than that of the initial state . By sharp contrast, it was 55.2% lower than the initial state for pristine SPEEK. And its swelling ratio is only 54% compared with 128% of pristine SPEEK under the same condition. We first revealed and investigated the acid-base pair created by PDA@PI and HPW/SPEEK, which was beneficial for proton conductivity and durability. This pocket-like PDA@PI/SPEEK + HPW membrane would inspire a wide application in PEM among excellent proton conductivity, better stability, with endurance.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Zhi Yang,Bowen Luo,Riyang Shu,Zhuojie Zhong,Zhipeng Tian,Chao Wang,Ying Chen
Hydrodeoxygenation (HDO) is an indispensable reaction in the field of fuel and chemical production, and the synergistic effect of metal–acid sites in the catalyst makes great influence to it. Herein, a bifunctional catalyst of Ru/C combined with phosphotungstic acid (HPW) was employed for the hydrodeoxygenation (HDO) of lignin-derived compounds to make full use of the synergistic effect of active metal–acid sites. HPW possessed a temperature-controlled phase-transfer behavior, which made it dispersed well on the surface of Ru/C catalyst and resulted in a close integration of acid site with metal site. Ru/C-HPW catalyst also owned the advantage of high reaction rate and good recyclability, which exhibited no obvious catalytic activity loss after 5 runs. Lignin-derived phenolic compounds including monomers and dimers enabled to obtain an efficient transformation to cycloalkanes at the temperature of 200 °C. Moreover, a high HDO reaction efficiency of raw lignin-oil was also observed in this study, with the increasing hydrocarbon content from 5.5% to 78.9%. This novel catalytic system can achieve a high HDO efficiency under mild conditions.
研究领域:
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2021
·Vol. 8
·期 14
·3463-3472
·
IF 6.569
Yao Yao,Kexin Huang,Yi Liu,Tingting Luo,Ge Tian,Jiaxin Li,Song Zhang,Ganggang Chang,Xiaoyu Yang
As a typical process-intensive strategy, a tandem reaction driven by a multifunctional catalyst is a paragon of the green catalytic process. Two or more active sites are usually required and their rational spatial distribution is critical for the multi-functional catalyst to act independently or synergistically. Here, we present a simple and stepwise method to construct a trifunctional integrated catalyst simultaneously with spatially intimate acidic (phosphotungstic acid (HPW)), basic (amino) and metal (Pd nanoparticles (NPs)) sites in hierarchically porous UiO-66-NH2. Through fine controlling the ratio of immobilized HPW and amino groups, we can easily tune its accessible acidic and basic properties, and the anchored HPW molecules can be effectively used to mediate the catalytic performance of Pd NPs and further stabilize the Pd sites. This well-designed integrated catalyst showed excellent catalytic activity and yield (>97%) towards one-pot three-step Deacetalization–Knoevenagel–Hydrogenation (D–K–H) catalysis reactions owing to the synergetic catalysis and the intimate spatial arrangement of the acid, basic and metal sites. More importantly, the trifunctional catalyst could be recycled at least five times without significantly losing its activity due to the strong interaction between the MOF and the guest molecules. This work provides some important insights into the construction of multifunctional integrated catalysts, especially for the application in challenging tandem catalysis.
研究领域:
催化
·
化学工程
·
材料科学
✓ 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）