JOURNAL OF POROUS MATERIALS
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2020
·Vol. 27
·期 4
·1003-1012
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IF 2.183
Ren Hui-Fang,Luo Xiao,Zhang Ke,Cai Qiang,Liu Chun-Ling,Dong Wen-Sheng
Heteroatom (N, B or P)-doped ordered mesoporous carbons (OMCs) supported Ru catalysts was utilized in the aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF). The characterization data showed that the heteroatom-doping of OMC promoted the dispersion of Ru nanoparticles on catalysts, which further improved their catalytic activities for the selective aerobic oxidation of HMF into DFF. Among the three kinds of heteroatom-doped Ru catalysts, the P-doped one displayed the best activity for the selective aerobic oxidation of HMF into DFF. From Ru/OMC-P0.56, 100% of HMF conversion, 88% of DFF yield with a high activity of 68.7 h −1 were achieved at 90 °C for 4 h under 2 MPa O 2 in toluene. Partial inactivation of catalyst was observed in the recycling runs, which might be attributed to the deposition of humins on catalyst and the agglomeration of Ru particles.
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ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Xuemei Li,Junying Tian,Hailong Liu,Xun Hu,Jia Zhang,Chungu Xia,Jing Chen,Haichao Liu,Zhiwei Huang
The reductive amination (RA) of 2-hydroxytetrahydropyran (2-HTHP) produced from biofurfural-derived dihydropyran provides a new efficient process for the clean synthesis of valuable 5-amino-1-pentanol (5-AP). Among various solid catalysts tested, the inexpensive Ni–Mg3AlOx catalysts derived from hydrotalcite precursors were found to be very active and selective, especially at Ni loadings above 20 wt %. A 85% total yield of 5-AP was obtained from dihydropyran on 40Ni–Mg3AlOx, the catalyst with the highest 2-HTHP RA activity among the Ni–Mg3AlOx catalysts, under mild conditions of 60 °C and 2 MPa H2. Characterization results showed that the reducibility of the calcined NiO-Mg3AlOx samples increased with increasing Ni loading from 5 to 50 wt %, while the Ni0 crystallite sizes exhibited a minimum of 4.8 nm on 40Ni–Mg3AlOx after reduction in H2 at 750 °C. The volcanic changes of 5-AP generation rate/yield with increasing Ni loading of the Ni–Mg3AlOx catalysts and with rising prereduction temperature of 30Ni–Mg3AlOx catalyst in 2-HTHP RA indicate that the balance of the reducibility and Ni0 particle size of the catalysts played an important role in obtaining high 5-AP yields. The 30Ni–Mg3AlOx catalyst showed a good stability in 2-HTHP RA examined in a continuous flow reactor over a 90 h time-on stream.
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FUEL
·
2020
·
IF 5.578
Guo Qiu,Biaohua Chen,Chongpin Huang,Ning Liu,Xiuliang Sun
Methods for the conversion of carbohydrates into 5-hydroxymethylfurfural (5-HMF), which is an important platform chemical, have been attracted extensive attention. In present study, Sn modified ionic liquid polymer (PIL-Sn) was prepared by one-pot polymerization of imidazole and epichlorohydrin, and utilized as a novel and efficient catalyst for 5-HMF production. The optimal 5-HMF yield of 51.1% with 99% conversion was obtained from glucose catalyzed by PIL-Sn in dimethyl sulfoxide at 130 °C with reaction time of 1 h. This catalytic system can also be applied for the transformation of other carbohydrates with satisfactory yields. The mechanism of PIL-Sn-catalyzed conversion of glucose to 5-HMF has been studied using density functional theory (DFT) calculations. The DFT results showed that the five-coordinated SnCl 5 - as a preferred species played an important role in the isomerization of glucose to fructose. This research provides a new strategy to design efficient catalysts for 5-HMF synthesis.
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ENERGY CONVERSION AND MANAGEMENT
·
2020
·
IF 8.208
Changsong Hu,Huiyan Zhang,Shiliang Wu,Rui Xiao
This article is intended to deepen the understanding of molecular shape selectivity of HZSM-5 in catalytic conversion of biomass pyrolysis vapors through the study of catalyst effective pore size. Ex-situ catalytic fast pyrolysis (CFP) of biomass over HZSM-5 with varied catalyst loadings were carried out using a continuous feeding two-stage fluidized-bed/fixed-bed combination reactor. Results showed that in addition to the shape selective reactions inside catalyst channels, cracking and aggregating reactions occur at the external surface of HZSM-5. The catalytic activity of HZSM-5 external surface for some heavy compounds was observed to be relatively low. On the basis of the molecular dimension information provided by quantum chemical calculations, it was found that HZSM-5 has an effective pore size which is significantly larger than its static pore size at CFP temperature. Catalytic alkylation of naphthalene with methanol over HZSM-5, HZSM-5@silicalite-1, HSAPO-34, HM, Hβ, HUSY and HMCM-41 were further compared to determine the effective pore size of HZSM-5. It is proposed that the effective pore size of HZSM-5 at CFP temperature is between the critical molecular diameters of 2,3- and 1,6-dimethylnaphthalene (between 7.520 and 7.961 Å).
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JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A
·
2020
·Vol. 108
·期 12
·2435-2446
·
IF 3.525
Zhen Yu,Shisi Ma,Mengfan Wu,Huan Cui,Rong Wu,Sizhe Chen,Chenlin Xu,Xiaohe Lu,Songfu Feng
The vitreous substitute for proliferative vitreoretinopathy (PVR) surgery remains an unmet clinical need in ophthalmology. In our study, we developed an in situ formed hydrogel by crosslinking polyvinyl alcohol (PVA) and chitosan as a potential vitreous substitute. 5-fluorouracil (5-FU) Poly (lactic-co-glycolic acid) (PLGA) microspheres were developed and loaded onto the PVA/chitosan hydrogels to treat PVR. In vitro, PVA/chitosan hydrogels at four concentrations were subjected to morphological, physical, rheological analyses, and cytotoxicity was evaluated together with the characterization of 5-FU PLGA microspheres. In vivo, pharmacologically induce PVR rabbits were performed a vitrectomy. In the PVA group, 3% PVA/chitosan hydrogel was injected into the vitreous cavity. In the PVA/MS group, 3% PVA/chitosan hydrogel and 5-FU PLGA microspheres were injected. In the Control group, phosphate-buffered saline was injected. Therapeutic efficacy was evaluated with postoperative examinations and histological analyses. This study demonstrated that the 3% PVA/chitosan hydrogel showed properties similar to those of the human vitreous and could be a novel in situ crosslinked vitreous substitute for PVR. Loading 5-FU PLGA microspheres onto this hydrogel may represent an effective strategy to improve the prognosis of PVR.
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ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Yue Zhang,Linfang Li,Ye Gao,Xinnan Wang,Lei Sun,Wei Ji,Yukihiro Ozaki
Urinary 5-hydroxyindole-3-acetic acid (5-HIAA) is a marker for diagnosis of patients with carcinoid tumors. In clinical practice, a simple colorimetric assay has widely been utilized for urinary 5-HIAA via its reaction with 1-nitroso-2-naphthol (NNa) in nitrous acid medium. However, this colorimetric assay has been criticized for lack of specificity. Herein, we proposed a novel SERS-based method for selective detection of urinary 5-HIAA by the use of a modified nitrosonaphthol reaction, in which hydrochloric acid is substituted for nitric acid to control the reaction conditions. This slight modification is crucial to be able to detect the cationic products in the acidic reaction mixture, because the chloride-aggregated Ag colloids not only create enormous hot spots for SERS enhancement, but also improve the chemical stability of nanostructured Ag substrates in acidic environment. Under optimized conditions, the present method can detect 5-HIAA within 12 min at concentrations as low as 1.2 ng/mL, which is 1000 times lower than that of conventional colorimetric method . And more importantly, the present method exhibits specific response toward 5-HIAA against other metabolites with similar structures in the urine. The relative standard deviation (RSD) of the present method is less than 5%, suggesting the acceptable reproducibility. The recoveries ranging from 89.6% to 106.3% were obtained for spiked human urine samples with RSD of 3.7–4.9%. Furthermore, several healthy person’s urine samples were also analyzed using the present method, and experimental results are in compliance with the levels recorded in a healthy population. On the basis of these results we can conclude that the present SERS-based method can provide a valuable alternative to conventional colorimetric assay for clinical diagnosis, evaluating prognosis, and monitoring of treatment in carcinoid tumors.
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ChemSusChem
·
2020
·Vol. 13
·期 12
·3127-3136
·
IF 7.962
Peter Kisszekelyi,Rifan Hardian,Hakkim Vovusha,Binglin Chen,Xianhai Zeng,Udo Schwingenschlögl,Jozsef Kupai,Gyorgy Szekely
Graphical Up the tempo : An efficient TEMPO-based electrocatalytic transformation of biomass-based C 6 -platform chemical 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) is reported. The molecular design and comparison of homogeneous (native, size-enlarged) and solid-supported (SiliaCAT, TurboBeads) TEMPOs is discussed for the oxidation in the ElectraSyn reactor with cost-effective electrodes and green solvents. Computational modeling reveals the synergistic effect of the catalyst/base system and facilitated the catalyst design. The catalytic transformation of bio-derived compounds, specifically 5-hydroxymethylfurfural (HMF), into value-added chemicals may provide sustainable alternatives to crude oil and natural gas-based products. HMF can be obtained from fructose and successfully converted to 2,5-diformylfuran (DFF) by an environmentally friendly organic electrosynthesis performed in an ElectraSyn reactor, using cost-effective and sustainable graphite (anode) and stainless-steel (cathode) electrodes in an undivided cell, eliminating the need for conventional precious metal electrodes. In this work, the electrocatalysis of HMF is performed by using green solvents such as acetonitrile, γ-valerolactone, as well as PolarClean, which is used in electrocatalysis for the first time. The reaction parameters and the synergistic effects of the TEMPO catalyst and 2,6-lutidine base are explored both experimentally and through computation modeling. The molecular design and synthesis of a size-enlarged C 3 -symmetric tris-TEMPO catalyst are also performed to facilitate a sustainable reaction work-up through nanofiltration. The obtained performance is then compared with those obtained by heterogeneous TEMPO alternatives recovered by using an external magnetic field and microfiltration. Results show that this new method of electrocatalytic oxidation of HMF to DFF can be achieved with excellent selectivity, good yield, and excellent catalyst recovery.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2020
·
IF 5.162
Tingwei Zhang,Wenzhi Li,Yongcan Jin,Wenhui Ou
A novel sulfonated chitosan-derived carbon-based catalyst was successfully prepared via isoamyl nitrite-assisted sulfanilic acid sulfonation , and its catalytic activity was examined using dehydration of fructose. The structural and chemical properties of sulfonated chitosan-derived carbon were characterized by SEM, FTIR, XRD, XPS , element analysis, N 2 adsorption-desorption experiment, and acid-base titration experiment. KOH was used as activating agent in the synthesizing of carbon supports, and it was found that properly increasing the dose of KOH during activation stage had a positive effect on the subsequent sulfonation of prepared activated carbon. 4KSCC, with the highest sulfonation degree (2.04 mmol/g), exhibited high performance for the conversion of fructose to HMF in various solvent, and an optimal HMF yield of 80.9% was obtained at 140 °C in 40 min. In addition, the reusability of 4KSCC for fructose dehydration was fairly good.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Jiashi Wang,Qinhong Wei,Qingxiang Ma,Zhongya Guo,Fangfang Qin,Zinfer R. Ismagilov,Wenzhong Shen
At present, the increasing consumption of fossil fuels as well as the expanding of more effective avenues to prepare carbon materials have inspired scholars' confidence to seek for alternative carbon sources. To address this issue, a N-doped graphene shell encapsulated metallic Co (Co@NGs) catalyst was fabricated using glucose and melamine as carbon source and nitrogen source via carbonization and employed for 5-hydroxylmethylfurfural (HMF) hydrogenation to produce 2,5-dimethylfuran (DMF) biofuel. Here, the prepared Co@NGs catalyst which possessed striking Mott-Schottky effect presented strong electronic interaction at the interface of surface metallic Co and doped N, leading to the electron transfer from metallic Co to doped N on carbon substrate. Experimental results indicated that the decreased electron density of metallic Co was more conductive to selective catalytic hydrogenation of HMF to form DMF. More importantly, the catalytic activity of the Mott-Schottky-type Co@NGs catalyst could be regulated by adjusting the nitrogen content. That is, the high nitrogen content increased the work function of Co@NGs and thus the enhanced rectifying response at the interface by which to enhance the catalytic performance. The best Co@NGs catalyst exhibited both high HMF conversion (close to 100 %) and DMF selectivity (94.7 %), much better than those of conventional N-doped carbon supported Co catalysts.
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Materials
·
2019
·Vol. 12
·期 23
·3948
·
IF 2.972
Lingfang Qiu,Zhiwei Zhou,Mengfan Ma,Ping Li,Jinyong Lu,Yingying Hou,Xiangshu Chen,Shuwang Duo
Novel visible-light responded aluminosilicophosphate-5 (SAPO-5)/g-C3N4composite has been easily constructed by thermal polymerization for the mixture of SAPO-5, NH4Cl, and dicyandiamide. The photocatalytic activity of SAPO-5/g-C3N4is evaluated by degrading RhB (30 mg/L) under visible light illumination (λ > 420 nm). The effects of SAPO-5 incorporation proportion and initial RhB concentration on the photocatalytic performance have been discussed in detail. The optimized SAPO-5/g-C3N4composite shows promising degradation efficiency which is 40.6% higher than that of pure g-C3N4. The degradation rate improves from 0.007 min−1to 0.022 min−1, which is a comparable photocatalytic performance compared with other g-C3N4-based heterojunctions for dye degradation. The migration of photo-induced electrons from g-C3N4to the Al site of SAPO-5 should promote the photo-induced electron-hole pairs separation rate of g-C3N4efficiently. Furthermore, the redox reactions for RhB degradation occur on the photo-induced holes in the g-C3N4and Al sites in SAPO-5, respectively. This achievement not only improves the photocatalytic activity of g-C3N4efficiently, but also broadens the application of SAPOs in the photocatalytic field.Keywords:g-C3N4;SAPO-5;composite;photocatalytic;visible light
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Siqian Zhang,Cheng Zhang,Qiang Wang,Wha-Seung Ahn
A series of ZSM-5 catalysts were synthesized using fly ash from power plants and red mud from aluminum production in different weight ratios. The ZSM-5 was subsequently coimpregnated with Co and Mn and tested for the low-temperature selective catalytic reduction of NOx by NH3 (NH3-SCR). These catalysts were characterized by XRD, N2-adsorption isotherms, SEM, XPS, and H2-TPR. Among all the prepared catalysts, 5 wt % Co 10 wt % Mn/ZSM-5 had shown the best catalytic activity, with 98.8% conversion of NOx and 90.7% selectivity toward N2 at 150 °C. This is comparable to the performance of a similar ZSM-5 catalyst prepared using chemical reagents. The high ratio of Mn4+/(Mn4+ + Mn3+ + Mn2+) in the catalyst improved the NOx conversion, whereas the moderate redox property imparted by Co3+ led to high N2 selectivity. This catalyst also showed strong resistance against poisoning in 100 ppm SO2 and 5% H2O. This work demonstrates that effective NOx removal treatment with high N2 selectivity and sufficient stability for either cement plants or incinerators can be achieved by using a porous catalyst/support material produced from industrial solid wastes.
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DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 48
·18473-18479
·
IF 4.569
Yan Zhou,Shanshan Lv,Han Li,Qikang Wu,Taiyu Chen,Shaohuan Liu,Wanying Li,Wenjuan Yang,Zheng Chen
The development and transformation of biomass-derived platform compounds is a sustainable way to deal with the fossil fuel crisis. 5-Hydroxymethylfurfural (HMF) can be reduced or oxidized to produce many high-value compounds; however, it is challenging to effectively produce 2,5-diformylfuran (DFF) due to overoxidation. In this work, a carbon-doped V2O5 (C–V2O5) material was obtained through pyrolysis of MIL-47(V) nanorods, a typical metal–organic framework material. The X-ray diffraction patterns and X-ray photoelectron spectra showed that the graphitized carbon species were incorporated in C–V2O5. High-efficiency HMF oxidation, high specific selectivity for DFF and excellent recycling could be achieved with the C–V2O5 catalyst. Fourier-transform infrared spectroscopy combined with density functional theory (DFT) calculation revealed that graphitized carbon weakens the VO bond and promotes the formation of oxygen vacancies in C–V2O5, thus improving the catalytic activity in the oxidation of furfuryl alcohols. The V4+ induced by oxygen vacancies will be oxidized by O2 to form V5+, so that the cycle can be realized. It exhibits remarkable selectivity in the oxidation of different alcohols produced from biomass based on the relatively constant active sites in C–V2O5.
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