Molecular Catalysis
·
2023
·
IF 4.6
Bo Li,Haijun Guo,Zhen Xiong,Lian Xiong,Shimiao Yao,Mengkun Wang,Hairong Zhang,Xinde Chen
γ-valerolactone (GVL) is a sustainable chemical, which can be obtained by hydrogenation of levulinic acid (LA) and levulinate. Herein, we reported a solvent-free hydrogenation of butyl levulinate (BL) to GVL and 1,4-pentanediol (1,4-PDO) over a skeletal Cu-Al-Zn catalyst. The skeletal Cu-Al-Zn catalyst was prepared from Devarda's alloy by alkali leaching and the catalyst was characterized by different analysis methods. The aluminum in the Devarda's alloy was dissolved by sodium hydroxide in the leaching process and many active Cu atoms were generated on the catalyst surface and the skeletal Cu-Al-Zn exhibited many micrometer-scale irregular particles with rough surface. The skeletal Cu-Al-Zn catalyst showed the excellent performance in the solvent-free hydrogenation of BL to GVL under constant hydrogen pressure (5 wt% catalyst loading, 180°C, 6 MPa of H 2 , 6 h): the LA conversion was 100%, the GVL yield was 74.75% and the 1,4-PDO yield was 25.63%. Moreover, the catalyst showed stable performance and it was reusable up to 5 times without apparent loss of activity. A stable hydrogen pressure with Zn would suppressed the dehydration of 1,4-PDO.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 47
·期 3
·1256-1267
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IF 3.925
Lei Yin,Hui Yang Li,Tingting Ge,Yuchao Li,Cuncun Zuo,Ming Wang,GuangJun Cui,Haofei Huang,Lin Guo
A series of acid–base-loaded γ-Al2O3 catalysts was applied as the catalysts for the isomerization of 3/4-methyl-tetrahydro phthalic anhydride. With a basic metal (K or Na) as the basic source and phosphorus (P) as the acid source, γ-Al2O3 was modified by equal volume immersion. NH3/CO2-TPD, XRD, TEM/EDS, BET, and TGA were used to analyze the catalysts, and 15%-K/Al2O3 and 10%-P/Al2O3 were determined as the most appropriate catalysts. The isomers were qualitatively and quantitatively analyzed using nuclear magnetic resonance (1H-NMR) and infrared spectroscopy (IR), and the reaction mechanism for the isomer formation was proposed. With 3-MTHPA as the substrate, the acid/base reaction temperature was 165/150 °C, the reaction time was 3 h and the amount of the catalyst added was 3%. A new type of continuous isomeric fixed-bed reactor was designed. The stability of the catalyst was tested, and the activity loss was 4.6–6.6% after 10 hours of operation.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Yaqiao Liu,Shuozhen Hu,Xinsheng Zhang,Shigang Sun
Fe 2 O 3 is a promising n -type semiconductor as the photoanode of photoelectrochemical water-splitting method due to its abundance, low cost, environment-friendly, and high chemical stability. However, the recombination of photogenerated holes and electrons leads to low solar-to-hydrogen efficiency. In this work, to overcome the recombination issue, a p-type semiconductor, CuO, is introduced underneath the γ-Fe 2 O 3 to synthesize γ-Fe 2 O 3 /CuO on the FTO substrate. Along with the formation of p-n heterojunction , CuFe 2 O 4 is in situ generated at the interface of γ-Fe 2 O 3 and CuO. The existence of Cu 2 O in CuO and CuFe 2 O 4 promotes the charge transfer from CuO to γ-Fe 2 O 3 and within CuFe 2 O 4 , respectively, resulting in creating an internal electric field in γ-Fe 2 O 3 /CuO and leading to the conduction band of CuO bending up and γ-Fe 2 O 3 bending down. Additionally, Cu(II) in CuFe 2 O 4 contributes to fast electron capture. Consequently, the charge transfer efficiency and charge separation efficiency of photo-generated holes are promoted. Hence, γ-Fe 2 O 3 /CuO exhibits an enhanced photocurrent density of 13.40 mA cm −2 (1.9 times higher than γ-Fe 2 O 3 ). The photo corrosion resistance of CuO is dramatically increased with the protection of CuFe 2 O 4 , resulting in superior high chemical stability, i.e. 85% of the initial activity remains after a long-term test.
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高影响因子
CATALYSIS LETTERS
·
2023
·
IF 2.8
Xiang Yuchen,Zhang Huiming,Zhang Jingyi,Xu Qiong,Liu Xianxiang,Yin Dulin
Comprehensive use of available biomass, especially low-cost forestry waste to produce bioenergy, materials have great meaning for realization of green and sustainable chemical processes. In this work, forestry sawdusty waste (SD) was used to produce biochar (SDBC-P) via a H 3 PO 4 assisted hydrothermal carbonization method. And a novel zirconium-coordinated biochar catalyst Zr-SDBC-P has been prepared by self-assembly method. Characterization results revealed that hydrothermal carbonization in the presence of H 3 PO 4 promoted the formation of oxygen-containing functional groups (–COOH, Ar–OH) which were used as ligand to obtain high contents of Lewis acid − base sites (Zr 4+ –O 2− ). Zr-SDBC-P-4 showed satisfactory catalytic activity in synthesis of bioderived γ-valerolactone (GVL) from ethyl levulinate (EL). EL conversion of 98.2% and GVL selectivity of 85.4% were obtained within 5 h at 170 °C. In addition, Zr-SDBC-P-4 displayed outstanding chemical stability. There was no obvious decrease of GVL yield after being used for six cycles. Overall, this work offered a viewpoint to design catalyst from value-added utilization of biomass waste. Graphical Abstract
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FOOD AND AGRICULTURAL IMMUNOLOGY
·
2023
·
IF 3
Linyang Song,Xiaoyi He,Mengxia Wang,Lixia Li,Jing Liu,Guoying Li,Junhua Yang
People often simultaneously expose to acceptable/tolerable daily intake of food additives and pesticides in daily life. Exposure in adult rodents to acceptable/tolerable daily intake of food additives and pesticides chemical mixtures (AFACM) is reported to cause health damage. Our recently study reported that AFACM exposure of pregnant mice resulted in neuroinflammation and abnormal emotional behaviours in offspring. Here, we found that neutralising IFN-γ with neutralising antibodies completely blocked the influences induced by maternal AFACM exposure, including the increased IFN-γ level in serum, increased IFN-γ, interleukin-6 and tumour necrosis factor-α levels in prefrontal cortex(PFC) in offspring on postnatal day(PND)7, the abnormal emotional behaviours in offspring on PND56, and the decreased of ATPase phospholipid flippase 8A2(ATP8A2) in the PFC of offspring on PND7. In sum, maternal AFACM exposure induced the PFC neuroinflammation, abnormal emotional behaviours and decreased PFC ATP8A2 expression through increasing systemic IFN-γ in offspring.
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APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Jing Li,Tongtong Xia,Jiacheng Xu,Chunle Zhang,Li Xu,Zuliang Wu,Shuiliang Yao
CeO 2 /γ-Al 2 O 3 catalysts with distinct crystallite sizes were synthesized by changing the precursors of ceria. CeO 2 /γ-Al 2 O 3 prepared by cerium nitrate (CN) had smaller crystalline size than samples prepared by cerium chloride or cerium acetate. They were evaluated in the plasma catalytic oxidation reaction of n -undecane (C11), which is one of the representative long-chain alkane volatile organic compounds (VOCs). CeO 2 (CN)/γ-Al 2 O 3 displayed a higher C11 conversion of 100 % with 72 % of CO 2 selectivity under ambient conditions with an energy density of 205 J/L, while samples with larger crystalline sizes showed lower activities. X-ray photoelectron spectroscopy analysis confirmed that more concentration of adsorbed oxygen species and higher ratio of Ce 3+ /(Ce 3+ +Ce 4+ ) existed on the surface of CeO 2 /γ-Al 2 O 3 samples with smaller crystalline size. Chemisorption experiments further verified that surface oxygen vacancies resulted in the different catalytic activities. In situ diffuse reflectance infrared Fourier transform spectroscopy analyses showed that the oxidation capability of intermediates by-products enhanced with the decrease of crystalline size. Results revealed that the crystallite size of CeO 2 had a significant effect on the redox properties. This research provides an insight into the regulation of oxygen vacancy in transition metal oxides to facilitate the plasma catalytic performance of alkane VOCs under mild reaction conditions.
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RESEARCH ON CHEMICAL INTERMEDIATES
·
2022
·Vol. 48
·期 9
·3753-3772
·
IF 3.134
Hou Qingyao,Qin Langlang,Peng Xueer,Zhou Chenyang,Li Xuelian,Zhang Jiandong,Gao Lili
The development of catalysts with high catalytic activity and convenient recycling property is the long-term goal of sulfate-based advanced oxidation processes for the degradation of organic pollutants. In this work, a kind of iron/copper oxide hybrid catalyst (α-Fe 2 O 3 /γ-Fe 2 O 3 /Cu 2 O, CuFe-13) with both higher catalytic performance and paramagnetism was synthesized using a modified method for conventional CuFeO 2 . Through X-ray diffraction and infrared spectra characterization, the catalyst was verified a hybrid of α-Fe 2 O 3 , γ-Fe 2 O 3 and Cu 2 O, in which the exist of magnetic γ-Fe 2 O 3 was the main cause for CuFe-13’s paramagnetism and convenient magnetic recycling property. The mechanism for CuFe-13’s excellent catalytic performance was primarily investigated. Through scanning electron microscope, X-ray photoelectron spectroscopy, N 2 adsorption–desorption measurement, radical quenching experiments, and electron paramagnetic resonance characterization analysis, the CuFe-13 represented larger surface area, bigger porosity, more efficient synergistic effect among Cu, Fe, and O than CuFeO 2. The generation of various of reactive oxygen species (ROS), including sulfate radical ( \({\text{SO}}_{4}^{\cdot - }\) ), hydroxyl radical ( · OH), and singlet oxygen ( 1 O 2 ), especially 1 O 2 were more, which might lead to CuFe-13’s higher catalytic performance. The effects of PMS concentration, CuFe-13 dosage, initial pH, initial OG concentration were analyzed. The optimal removal efficiency of OG could be achieved 100% within 20 min with 1 mM PMS and 0.2 g L −1 CuFe-13 under neutral condition. This study provided an efficient PMS-activated catalyst for degradation of organic pollution.
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APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Hao Wang,Hongyou Yin,Zeng Zhang,Yan Wu,Chang Yi,Tingting Shen
γ-Cu 2 (OH) 3 Cl is used as a Fenton catalyst to mineralize phenol in high chloride solutions. The mineralization of phenol can be enhanced even at 15000 mg∙L –1 NaCl under ambient pH. In addition, other aromatic contaminants including bisphenol A , benzoic acid , 2-chlorophenol, salicylic acid and aniline can also be effectively mineralized under the high chloride concentration. However, reference catalysts including CuSO 4 , CuO and Cu 2 O are significantly depressed by chloride. The chloride resistance ability of γ-Cu 2 (OH) 3 Cl is proposed. First, σ-Cu-ligand complexes formed between Cu 2+ and phenolic hydroxyl can react with H 2 O 2 to promote the rapid reduction of Cu 2+ to Cu + , which are not hindered by chloride. Second, the self-redox property of γ-Cu 2 (OH) 3 Cl which initiates the electron transfer from H 2 O 2 to Cu 2+ to generate Cu + is improved by chloride. Third, the circumneutral pH could suppress HO• scavenging by chloride. The activation energies of phenol mineralization over γ-Cu 2 (OH) 3 Cl in chloride-free and high chloride solutions are 42.9 and 32.3 kJ∙mol –1 , respectively. Chloride does not change the phenol mineralization pathway but accelerates its degradation into small carboxylic acids.
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CONSTRUCTION AND BUILDING MATERIALS
·
2022
·
IF 7.693
Xiaotao Zhang,Shun Zhou,Han Zhou,Dongxu Li
In this study, the effect of the incorporation of GO and KH550 modified GO(MGO) on the microstructure, mechanical properties and hydration process of the cement-based composites has been discussed. It is observed that the MGO surface is grafted with the functional groups, which reduce the interlayer force, thus, the dispersibility in the cement paste is improved. In addition, compared with GO, the addition of MGO can further promote the hydration of cement, and optimize the content of the various hydration products owing to no impact on the types of the hydration products, thus, make the microstructure of the cement more uniform. At the same time, the incorporation of MGO can refine the CH crystal size, reduce the total porosity of the cement material, and promote the conversion of harmful pores to harmless pores, thus, making the cement-based materials more compact and effectively improving the mechanical properties.
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高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2022
·
IF 6.47
Pijun Gong,Feng He,Junlin Xie,Haitao Wu
Zn species that exist in the flue gas are dangerous toxicants for SCR catalysts, which will seriously damage its catalytic activity and service life. Hence, the multi-layered nanosheets γ-Al 2 O 3 with (110) facets were introduced into the CeTiOx catalyst to improve the Zn-poisoning resistance performance. Benefiting from the structural and compositional merits, as well as the superior reducibility, abundant acid sites, and chemisorbed oxygen, the 3%Zn–Ce 0.3 -Al 0.4 -Ti catalyst with multi-layered nanosheets structure exhibits excellent NH 3 -SCR activity, over 90% NO conversion between 240 °C and 340 °C. In addition, in situ DRIFTS results suggest the SCR reaction mainly follows L-H and E-R mechanisms on 3%-Ce 0.3 -Al 0.4 -Ti samples, result from the multi-layered nanosheets γ-Al 2 O structure improves the BET specific surface area and Ce 3+ , promotes the adsorption/activation of more NH 3 and NOx species. More interestingly, compared with CeO 2 and TiO 2 the Zn species prefer to absorbed on nanosheets γ-Al 2 O 3 with (110) facets, so it can effectively protect CeO 2 from poisoning as a sacrificial agent .
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Ying Zhao,Nan Li,Jie Shi,Yuanhua Xia,Bo Zhu,Ruiqi Shao,Chunying Min,Zhiwei Xu,Hui Deng
Although nanofiltration (NF) membrane as a new frontier technique had made significant progress in the field of lithium extraction from salt lakes, they still suffered from the conventional permeability–selectivity trade-off effect. In this study, γ-cyclodextrins(CDs) containing amphipathic cavities and polyethyleneimine (PEI) acted as the aqueous phase monomer, which was carried out interfacial polymerization with the trimesoyl chloride (TMC) as the organic phase monomer to fabricate thin film composite (TFC) NF membranes with the extra-thin active layer. The hydrophilic surface and hydrophobic cavity of γ-CDs enhanced the hydrophilicity of the membrane surface and the water flux of the nanofiltration membrane. Moreover, the cavity size of γ-CDs also effectively screened magnesium and lithium ions to a certain extent. Under the best preparation conditions, the permeation flux of the PEI/γ-CDs-TMC nanofiltration membrane was 4.86 L⋅m −2 ⋅h −1 ⋅bar −1 , S Li, Mg was 10.8. It was noteworthy that we used the molecular dynamics simulation method to confirm that the participation of γ-CDs led to the diffusion rate of the water phase monomers during the interfacial polymerization reaction slowed down. Thus, the thickness of the active layer of the nanofiltration membrane formed was also significantly reduced from 110.16 nm to 52.84 nm. This PEI/γ-CDs-TMC membrane provided a new strategy for preparing nanofiltration membranes with excellent overall magnesium-lithium separation performance.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Jingru Sun,Yang Sun,Guangyu Deng,Chunmiao Xia,Huan Liu,Siying Cheng,Zongcheng Miao,Cuige Zhang,Rongli Zhang
With the rapid science and technology advancement, the oil-water separation in oily wastewater has become an urgent problem, especially the emulsified oil-water mixtures. Hollow carbon spheres (HCSs) have tremendous potential in separating oil-water emulsions due to their rich porous channels and high surface-to-volume ratio. In this work, as-prepared chitosan/poly(γ-glutamic acid) nanoparticles crosslinked by Ni 2+ (Ni 2+ /CS/γ-PGA NPs) were used as carbon precursor to fabricate HCSs. This strategy separated the formation process of the biomolecular microspheres and the carbonization process. Especially, the Ni 2+ /CS/γ-PGA NPs were fabricated from the self-assembly of chitosan and γ-PGA in aqueous solution and the crosslinking of Ni 2+ via the electrostatic interactions, facilitating the formation of biomolecular microspheres and making the usable of biomolecule-based carbon precursors diversity. After lyophilization, Ni 2+ /CS/γ-PGA NPs powder was obtained, which was then carbonized in a tube furnace under N 2 atmosphere. During the carbonization process, the nickel species aggregated together to form the core of nickel@carbon nanoparticles, and carbon formed the shell. At last, nickel nanoparticles were removed from the carbon framework by hydrochloric acid, obtaining HCSs with super-hydrophobicity and lipophilicity . The as-prepared HCSs exhibited excellent separation performance in oil-in-water emulsions.
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高影响因子
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