Chemical Science
·
2018
·Vol. 9
·期 21
·4746-4755
·
IF 9.063
Congfang Chen,Aiping Wu,Haijing Yan,Yinglu Xiao,Chungui Tian,Honggang Fu
Bi-transition metal carbides (BTMCs) are promising in catalytic fields, but the synthesis of small-sized BTMCs remains a challenge. Here, MoxCoxC (mainly below 20 nm in size) confined in uniform carbon polyhedrons (MoxCoxC@C) was synthesized based on trapping [PMo12O40]3− (PMo12) clusters into pre-synthesized, uniform ZIF-67 (PMo/ZIF-67). The opening of the windows (0.34 nm) of ZIF-67 cages through heating is essential to allow the trapping of PMo12 into the cages. This trapping route provides a new method to successfully combine POMs and MOFs that can not be effectively combined via traditional POMOF-based (simultaneous assembly) routes. It also has advantages in controlling the uniformity and components of the materials. The size matching of PMo12 (1 nm) and the cages (1.16 nm) of ZIF-67 enables effective contact of the Co and Mo sources, thus giving small-sized MoxCoxC protected by carbon via calcination. The optimized catalysts showed good performance for water splitting with a low η10 of 83 mV (295 mV) for the hydrogen (oxygen) evolution reaction, which is superior to those derived from ZIF-67 and precursors from POMOF-based routes. Our results also indicated that the HER activity is determined by the kind of BTMC, and the activity for the OER is relative to the oxygen-containing species formed during the initial OER test.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2017
·
IF 3.752
Ting Lu,Yucui Hou,Weize Wu,Muge Niu,Yupeng Wang
Direct conversion of raw biomass to fine chemicals is of significant conceptual and practical interest. Up to now, the direct conversion of raw biomass to fine chemicals is still a big challenge. The oxidation of biomass to formic acid (FA) and acetic acid (AA) is a promising industrial process in the future. In this work, we reported that a binary catalyst system of Keggin-type heteropoly acid H 5 PV 2 Mo 10 O 40 + H 2 SO 4 was efficient to directly convert corn cob , a highly abundant renewable agricultural waste, to FA and AA using O 2 as the oxidant in aqueous solutions. The effects of catalyst amount, H 2 SO 4 concentration, reaction temperature, reaction time and initial O 2 pressure on the conversions of corn cob were investigated. Under optimized reaction conditions, corn cob was transformed with a FA yield of 42.5% and an AA yield of 9.1% (based on carbon) after 30 min of reaction at 170 °C. In the oxidation, the pH of the aqueous solution plays a key role. The influences of pH on solid degradation, reaction pathway and oxidation of the components of corn cob were discussed. Hemicellulose is oxidized rapidly followed by partly oxidation of lignin, and cellulose is the most difficult converted part. Products FA and AA mainly come from polysaccharides (hemicellulose and cellulose) and pH has a major influence on cellulose. The recycling of the catalyst system is demonstrated and shows good reusability .
研究领域:
生物化学
·
可再生资源利用
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 9
·4337-4345
·
IF 3.3
Zhangbin Liao,Yunlong Duan,Liying Guo,Rongrong Zheng,Liyan Wang,Yanming Chen,Linnan Zhang,Xin Qian
Five titanium-centered heteropoly acids with different metal vacancies were prepared first, and then combined with an ionic liquid by ion exchange to prepare heteropoly acid ionic liquid catalysts Bmim4–6[M(H2O)TiMo11O39] (M = Cu2+, Fe2+, Pb2+, Ti4+, and Zn2+). The structure and thermal properties of each catalyst were tested and analyzed by Fourier transform infrared (FTIR) spectroscopy, ultraviolet (UV) spectroscopy, X-ray powder diffraction (XRD), apparent morphology analysis, and thermogravimetric analysis (TGA). Five heteropoly acid ionic liquids were investigated by using waste mineral water bottles as samples for performance in the catalytic degradation of bottle-grade polyethylene terephthalate (PET), and the degradation product, bis(2-hydroxyethyl) terephthalate (BHET), was analyzed for the chemical structure. The results showed that the five heteropoly acid ionic liquid catalysts were successfully prepared, with good thermal stability. Of these catalysts, Bmim4[Ti(H2O)TiMo11O39] showed the optimal catalytic performance. It achieved an alcoholysis rate of 100% and a yield of BHET of 84.73% with a catalyst dosage of 0.6% (percentage in the total mass of the raw materials) at 190 °C for 5 h. Moreover, after six cycles of use, the alcoholysis rate was still as high as 94.36%, and the yield of BHET was 75.65%. The above results indicated that the prepared heteropoly acid ionic liquid catalysts showed good performance in the catalytic degradation of bottle-grade PET, presenting a promising prospect for development.
研究领域:
化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2024
·Vol. 26
·期 4
·2170-2182
·
IF 9.3
Zhuosen He,Yucui Hou,Jian Wei,Shuhang Ren,Weize Wu
Formic acid (FA) is a bulk chemical and a promising hydrogen energy carrier. The development of FA production from renewable biomass instead of multiple-step production from diminishing fossil resources is attractive. Formaldehyde (FAld) is another bulk chemical but industrial production requires high temperatures (250–600 °C). Herein, efficient oxidation of biomass to FA coupled with low-energy FAld production was developed using heteropoly acids as catalysts. Biomass and derivatives were oxidized to FA in yields of up to 88.6% while methanol was selectively oxidized to FAld at 90–190 °C with a markedly enhanced reaction rate. The synergistic mechanism has been unveiled that biomass activates methanol oxidation by boosting the catalytic redox cycle to form hydroxyl radicals and methanol scavenges the hydroxyl radicals to inhibit the overoxidation of biomass. This work opens up a promising direction for efficient FA production from biomass coupled with low-energy oxidation of alcohols to aldehydes.
研究领域:
化学工程
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Processes
·
2022
·Vol. 10
·期 2
·402
·
IF 3.352
Ziyang Zheng,Qian Wu,Shengyang Zhong
In this work, polyacrylamide (PAM) was first used in the loading of heteropoly acids, and then the HPM/PAM-n catalyst was synthesized by simple reaction. The FTIR and SEM measurements showed that the HPM/PAM-n (n = 10,000, 20,000, 30,000) was successfully synthesized. In addition, the HPM/PAM-n effect on desulfurization was measured, which showed the optimal desulfurization efficiency. The optimal process condition for HPM/PAM-10000 desulfurization was optimized by a single-factor experiment. The optimal condition was as follows: The temperature was 60 °C, the amount of the catalyst was 0.2 g, the oxygen to sulfur ratio was 16, and the reaction time is 100 min. The catalyst was suitable for recycled use, and the desulfurization efficiency was high after 10 times. In the end, the oxidative desulfurization mechanism was put forward.Keywords:PAM;desulfurization;heteropoly acid;recycle use
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Xin Huang,Guangchuan Tang,Lei Tang,Chuan Ma,Yunlin Shao,Jingyu Ran
Bio-based platform chemicals are of great significance to future green fine and commodity chemicals. This study reports the performances and mechanisms of solvothermal dehydration of levoglucosan (LGA), the main precursor from noncatalytic pyrolysis of cellulose with a yield up to 80 wt %, to levoglucosenone (LGO) using cesium heteropolyacid salts at the catalyst in DMSO solvent. Catalyst characterizations revealed that cesium was well doped in the cubic of heteropolyacids, and the cesium doping ratio substantially influenced the catalytic performances toward LGO. LGO yield first increased and then decreased with the increase of cesium doping ratios, which is consistent with the change trends of pore structures and Brønsted/Lewis acid site ratios of the cesium heteropolyacid salts. LGO was obtained with the maximum yield at 41.2% over Cs2H2SiW12O40 compared to 39.2% over Cs2.5H0.5PW12O40. The catalyst can be regenerated by calcination without losing its catalytic performances. In addition, density functional theory calculation was used to reveal the mechanism for LGO formation, and the rate-determining step was the first step of the dehydration reaction with the energy barrier of 166 kJ/mol.
研究领域:
化学工程
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可再生资源与环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2025
·
IF 2.4
Yu Lin,Yuanzhuo Ji,Yizhe Zhang,Hualiang An,Qian Zhao,Xinqiang Zhao,Yanji Wang
BACKGROUND Maleic acid (MAc) is a high value-added oxygenic hydrocarbon derivative monomer. The synthesis of MAc from biomass-based furfural is a green process and has important academic research value. Herein, selective catalytic oxidation of renewable furfural to MAc was investigated. RESULTS The effect of using different heteropoly acids as catalyst and different organic acids/H 2 O as solvent was evaluated first, and the ‘phosphomolybdic acid + acetic acid/H 2 O’ composite system with good performance was screened out. Acetate anion acted as free radical acceptor in the reaction to stabilize furfural radical and inhibit the polymerization reaction. Under optimal reaction conditions, the conversion of furfural was 97.8%, and the MAc yield and selectivity were 58.3% and 59.6%, respectively. To further improve the selectivity of MAc, different kinds of Lewis acids were introduced to construct a Brønsted–Lewis dual-acid catalytic system. When Cu(OAc) 2 was as Lewis acid, the MAc selectivity was significantly improved to 72.5% with a furfural conversion of 72.3%. The catalytic mechanism of Brønsted–Lewis dual-acid system was finally clarified. CONCLUSION In this complex system, the synergy of Cu and Mo is responsible for the outstanding catalytic efficiency, where the Mo VI /Mo V redox can be facilitated by the redox of Cu II /Cu I with the assistance of O 2 ; acetate anion can interact with furfural radicals, thereby delaying the chain reaction of free radicals. This process makes the MAc generation reaction more dominant than the polymerization reaction, thus improving MAc selectivity. © 2025 Society of Chemical Industry (SCI).
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2016
·Vol. 18
·期 17
·4725-4732
·
IF 8.506
Ting Lu,Muge Niu,Yucui Hou,Weize Wu,Shuhang Ren,Fan Yang
The preparation of formic acid (FA) by catalytic oxidation of sustainable biomass is of significant conceptual and practical interest, because FA is an important chemical and is now produced from non-sustainable fossil fuel. In this work, we found that a binary catalyst of Keggin-type heteropoly acid H5PV2Mo10O40 + H2SO4 was efficient in oxidizing biomass cellulose to FA using oxygen as an oxidant in aqueous solution. In the oxidation, the pH of the aqueous solutions plays a key role, and a decrease in pH improves the transformation. Cellulose was transformed to FA with conversions from 60% to 100% and FA yields from 28% to 61% (based on the carbon atoms in the feedstock) after 5 min of reaction at 180 °C, using H2SO4 as an additive to decrease the pH from 1.79 to 0.56. The influences of the pH on both the catalyst and the reaction pathway were discussed. By decreasing the pH, the oxidation potential and electron affinity were increased due to the formation of protonated H5PV2Mo10O40 and VO2+ species, favoring the reduction of the catalyst and oxidation of the substrate. A reaction pathway for the generation of products was proposed, and the influence of the pH on the reaction pathway was also discussed.
研究领域:
化学工程
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生物质能
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2012
·Vol. 108
·期 2
·531-544
·
IF 0.829
He Min-Qiang,Pan Ai-Xia,Xie Ji-Min,Jiang De-Li,Yuan Xin-Hua,Chen Min
Phosphotungstic heteropoly acid (PW) supported on various oxides (SiO 2 , TiO 2 , K-10 montmorillonite and γ-Al 2 O 3 ) were synthesized and used as catalysts for Friedel–Crafts acylation of pyrene with acetic anhydride to 1-acetylpyrene for the first time. The as-prepared catalysts were characterized by specific surface area measurement, X-ray diffraction, infrared spectroscopy, and temperature programmed desorption of ammonia. SiO 2 -supported phosphotungstic heteropoly acid (PW/SiO 2 , 40 wt%) was found to be the most active catalyst in the acylation giving 91.8 % yield and 100 % selectivity for 1-acetylpyrene at reaction temperature of 60 °C under ambient pressure. The effect of PW Loading, PW/SiO 2 amount, molar ratio of reactants, reaction temperature and reaction time on the catalytic acylation reaction were studied in detail to optimize the process parameters. The reusability of the PW/SiO 2 catalyst was appraised, and the possible pathway for the production of the Friedel–Crafts acylation of pyrene with acetic anhydride catalyzed by phosphotungstic heteropoly acid was also discussed briefly.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 17
·4238
·
IF 4.2
Zhuoyi Ren,Jiangfen Sheng,Qibin Yuan,Yizhen Su,Linhua Zhu,Chunyan Dai,Honglei Zhao
The combustion of fuel with high sulfur concentrations produces a large number of sulfur oxides (SOx), which have a range of negative effects on human health and life. The preparation of catalysts with excellent performance in the oxidative desulfurization (ODS) process is highly effective for reducing SOxproduction. In this paper, cross-linked polyvinylimidazole (VE) was successfully created using a simple ontology aggregation method, after which a catalyst of polyvinylimidazolyl heteropolyacid clusters (VE-HPA) was prepared by adding heteropolyacid clusters. Polyvinylimidazolyl-phosphotungstic acid (VE-HPW) showed an outstanding desulfurization performance, and the desulfurization efficiency reached 99.68% in 60 min at 50 °C with H2O2as an oxidant. Additionally, the catalyst exhibited recyclability nine consecutive times and remained stable, with a removal rate of 98.60%. The reaction mechanism was eventually proposed with the assistance of the free radical capture experiment and GC-MS analysis.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2020
·
IF 2.87
Qin Wu,Quan Shi,Jiqing Shang,Min Wang,Hansheng Li,Daxin Shi,Yun Zhao,Qingze Jiao
Surface-active heteropolyacid-based ionic liquids with varying alkyl carbon chains were synthesized, which were subsequently analyzed. The desulfurization of fuels was investigated utilizing various surface-active heteropolyacid-based ionic liquids, and acetonitrile was used as the extractant for the coupling of ODS and EDS. The influences of the alkyl group, surface activity, and hydrophobicity of ionic liquids on sulfur removal were studied. The results suggested that the ionic liquids were stable. Among these ionic liquids, [C4ImBS]3[PW12O40] exhibited the best catalytic performance. Using [C4ImBS]3[PW12O40] as the catalyst, the influences of the catalyst amount, aqueous hydrogen peroxide amount, and reaction temperature on the sulfur removal were explored. Under the optimum conditions, the sulfur removal could achieve 100% efficiency. The recycle experiments also proved that the ionic liquid could be reused.
研究领域:
催化化学
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2020
·Vol. 10
·期 12
·2449
·
IF 4.324
Shiliang Heng,Lei Li,Weiwei Li,Haiyan Li,Jingyu Pang,Mengzhen Zhang,Yan Bai,Dongbin Dang
The development of high-efficiency, recyclable, and inexpensive photocatalysts for water splitting for hydrogen production is of great significance to the application of solar energy. Herein, a series of graphene-decorated polyoxoniobate photocatalysts Nb6/PPy-RGO (Nb6= K7HNb6O19, RGO = reduced graphene oxide, PPy = polypyrrole), with the bridging effect of polypyrrole were prepared through a simple one-step solvothermal method, which is the first example of polyoxoniobate-graphene-based nanocomposites. The as-fabricated photocatalyst showed a photocatalytic H2evolution activity without any co-catalyst. The rate of 1038 µmol g−1in 5 h under optimal condition is almost 43 times higher than that of pure K7HNb6O19·13H2O. The influencing factors for photocatalysts in photocatalytic hydrogen production under simulated sunlight were studied in detail and the feasible mechanism is presented in this paper. These results demonstrate that Nb6O19acts as the main catalyst and electron donor, RGO provides active sites, and PPy acted as an electronic bridge to extend the lifetime of photo-generated carriers, which are crucial factors for photocatalytic H2production.Keywords:polyoxoniobate;Nb6/PPy-RGO composites;electronic bridge;H2production
研究领域:
材料科学
·
能源科学
✓ 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）