GREEN CHEMISTRY
·
2022
·Vol. 24
·期 22
·8840-8852
·
IF 11.034
Zongyang Liu,Yuan Tan,Jie Li,Xiuli Li,Yan Xiao,Juan Su,Xingkun Chen,Botao Qiao,Yunjie Ding
Aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) is a promising alternative route to produce renewable biodegradable plastics, which has stimulated intense interest in recent years. Supported gold catalysts have shown great potential for this reaction, but the selectivity and stability need to be improved. In addition, the requirement for base additives makes the process less effective and sustainable. Herein, highly active and selective Au–Ag bimetallic nanoclusters supported on MgAl-hydrotalcite (HT) were developed for HMF oxidation to FDCA under base-free reaction conditions using molecular oxygen as the oxidant. The presence of small amounts of Ag (0.034–0.065 wt%) in Au25 clusters greatly enhanced the catalytic reaction rates and selectivity for HMF tandem oxidative steps, leading to both high conversion of HMF (>97%) and high yield of FDCA (>95%). Besides, the catalyst stability was also enhanced by the addition of Ag. The characterization results suggested that the substitution of Ag atoms modified the electronic structure of Au while likely maintaining the primary geometry. Thus, a significant synergistic effect could be observed over trace Ag modified Au–Ag bimetallic nanoclusters. The present work provides new insight into the alloying effect, and helps understand highly efficient Au-based catalysts for aerobic oxidation of biomass derived molecules under base-free conditions.
研究领域:
催化化学
·
可再生资源化学
✓ 已验证
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2017
·
IF 0
Meng Xia Qian,Jian Li Ma,Min Hong Xu
A novel supported catalyst is prepared through immobilization of water soluble phthalocyanine, which is synthesized by modifying tetraminophthalocyanine with cyanuric chloride, onto the supporting material Mg-Al hydrotalcite via co-precipitation method. The structure of the catalyst is characterized by infrared spectroscopy instrument (FT-IR) and X-ray diffractometer. Catalytic activity is examined through comparative experiments. The results show that it exhibits high catalytic activity for degradation of methylene blue (MB) in the presence of H2O2, the remaining rate of MB is 12.02% after 6 h. The reaction process conforms to the equation of pseudo-first-order kinetics, and the correlation coefficient R2> 0.99. The recycling tests for five times are also carried out and prove its reusability in catalytic application.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Siqi Lei,Sinong Wang,Boxu Gao,Yulu Zhan,Qiancheng Zhao,Shanshan Jin,Guoxin Song,Xinchun Lyu,Yahong Zhang,Yi Tang
A high-performance dye adsorbent of ultrathin dodecyl-sulfate (DS − ) intercalated Mg-Al layered double hydroxide nanosheets (DI-LDH Ns) were controllably synthesized by a simple one-step surfactant-assisted hydrothermal method. The unique intercalated structure with week interlayer interaction and high accessible surface of DI-LDH Ns provide efficient adsorption of methyl orange (MO), leading to its superior performance with much higher uptake capability (846.6 mg/g at 298 K) and less adsorbing equilibrium time (5 min) than those of ultrathin DS − -surface-modified Mg-Al-LDH nanosheets (DM-LDH Ns, 327.4 mg/g at 298 K, 120 min) and original Mg-Al-LDH (O-LDH, 208.2 mg/g at 298 K, 120 min). The composition and structure of these LDHs were investigated by systematic physicochemical characterization, such as XRD, TEM, FT-IR, BET and TGA. The adsorption behavior of DI-LDH Ns follows the Langmuir isotherm equation. A plausible mechanism is proposed to explain the adsorption process of such DI-LDH Ns, in which the synergistic contributions of surface and interlayer adsorption between DI-LDH Ns and MO play an important role. This study puts forward a new thought for the development of high-performance LDH adsorbents with an ultrathin intercalated structure for the efficient and rapid removal of dyes.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
CELLULOSE
·
2020
·Vol. 28
·期 1
·301-316
·
IF 4.21
Yang Cong,Yuan Jun,Guo Yi,Luo Xiaogang
In this work, Mg/Al layered double hydroxides embedded phosphorylated cellulose microspheres (Mg/Al LDH@PCMs) were prepared first with solid-phase phosphorylation on CMs then in situ nano-assembly between Mg 2+ , Al 3+ and phosphate groups. Hence the synthesis degree of Mg/Al LDH was enhanced. The obtained Mg/Al LDH@PCMs were characterized by scanning electron microscopy (SEM), specific surface area test (BET), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ζ potential, X-ray electron energy (XPS). The novel in situ nano-assembly method provided improved Mg/Al LDH load without compromising the porous structure of CMs, making Mg/Al LDH@PCMs suitable for water treatment. The Mg/Al LDH@PCMs adsorbed tetracycline hydrochloride (TC) with a kinetic pattern of pseudo second-order kinetic model, while isothermally fitted with the Freundlich isotherm model. The maximum theory adsorption capacity of Mg/Al LDH@PCMs q m was 25.107 mg g −1 with the Gibbs free energy ∆G = 7.523 kJ mol −1 under 298 K. The TC removal mechanism was deeply investigated via characterization results and also the batch experimental results, it was inferred that electrostatic attraction between LDH particles and the anion species mainly dominated the adsorption process. These properties make Mg/Al LDH@PCMs have a wide application prospect in the water purification field.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Shanshan Zhou,Jialin Li,Jun Zeng,Yuewen Huang,Bin Wang
This study developed a novel organic-inorganic hybrid composite, shortly as GO-PEG-LDHs, by self-assembly of exfoliated Mg–Al layer double hydroxide (LDHs) on the polyethylene glycol (PEG) grafted graphene oxide (GO) to achieve the selective adsorption of hemoglobin (Hb). The prepared GO-PEG-LDHs has a hierarchical structure with a homogeneous loading of exfoliated LDHs nano-sheets on its surface. The adsorption test reveals that GO-PEG-LDHs exhibits an adsorption efficiency of 95.03% for Hb and 3.45% for bovine serum albumin (BSA). The adsorption of Hb follows the Langmuir model, with an ultrahigh adsorption capacity of 55248.6 mg/g, which is higher than any previously reported materials. Meanwhile, the adsorbed Hb can be efficiently recovered through elution with a 50 mM Tris-HCl buffer, with an elution efficiency of 80.77%. Circular dichroism (CD) spectra indicate no conformational change for Hb during the process of adsorption/desorption. Furthermore, the composite demonstrates the ability to selectively isolate Hb in the presence of interfering protein BSA, indicating its potential for practical applications.
研究领域:
材料科学
·
生物医学工程
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers of Chemical Science and Engineering
·
2024
·Vol. 18
·期 4
·1-15
·
IF 4.3
Guo Yunyu,Wang Yiran,Shao Yuewen,Zhang Shu,Wang Yi,Hu Song,Xiang Jun,Hu Xun
During steam reforming, the performance of a catalyst and amount/property of coke are closely related to reaction intermediates reaching surface of a catalyst. Herein, modification of reaction intermediates by placing Mg-Al-hydrotalcite above Ni/KIT-6 catalyst in steam reforming of glycerol was conducted at 300 to 600 °C. The results revealed that the catalytic activity of Ni/KIT-6 in the lower bed was enhanced with either Mg 1 -Al 5 -hydrotalcite (containing more acidic sites) or Mg 5 -Al 1 -hydrotalcite (containing more alkaline sites) as upper-layer catalyst. The in situ infrared characterization of steam reforming demonstrated that Mg-Al-hydrotalcite catalyzed the deoxygenation of glycerol, facilitating the reforming of the partially deoxygenated intermediates over Ni/KIT-6. Mg-Al-hydrotalcite as protective catalyst, however, did not protect the Ni/KIT-6 from formation of more coke. Nonetheless, this did not lead to further deactivation of Ni/KIT-6 while Mg 5 -Al 1 -hydrotalcite even substantially enhanced the catalytic stability, even though the coke was much more significant than that in the use of single Ni/KIT-6 (52.7% vs. 28.6%). The reason beneath this was change of the property of coke from more aliphatic to more aromatic. Mg 5 -Al 1 -hydrotalcite catalyzed dehydration of glycerol, producing dominantly reaction intermediates bearing C=C, which formed the catalytic coke of with carbon nanotube as the main form with smooth outer walls as well as higher aromaticity, C/H ratio, crystallinity, crystal carbon size, thermal stability, and resistivity toward oxidation on Ni/KIT-6 in the lower bed. In comparison, the abundance of acidic sites on Mg 1 -Al 5 -hydrotalcite catalyzed the formation of more oxygen-containing species, leading to the formation of carbon nanotubes of rough surface on Ni/KIT-6.
研究领域:
催化
·
化学工程
·
材料科学
·
能量转换
·
表面化学
✓ 已验证
DOI
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
·
2021
·Vol. 32
·期 3
·973-983
·
IF 3.543
Yu Mingwei,Zhang Lianhong,Wen Jie,Zhang Hui,Liu Faping,Lv Yanjun,Zhao Xiaodong
The remove of the organic pollutants in water plays an important role on the environmental protection, thus photocatalysis, as an effective method, has been attained much attention to deal with this problem. In this paper, a composite of g-C 3 N 4 and Mg–Al hydrotalcite derived metal oxides was prepared by simple co-precipitation methods followed by calcination. The effective adsorption-photocatalysis synergic effect and highly efficient removal of organic pollutants from water under simulated sunlight irradiation was found in the presence of fabricated metal oxide nanocomposites. The photocatalytic degradation rate of methylene blue reached 97.3% within 1 h under visible light, and the degradation rate constant was 0.0432 min −1 , which is 3.6 times that of g-C 3 N 4 . Though characterization analysis, more active sites are exposed to absorb more organic pollutants on the mater surface in the presence of the open hierarchical structures of composite materials, and the "face to face" contact structure between 2D materials is formed to promote the separation of electrons and holes. The photocatalytic degradation was stable in the recycling process of the catalyst. In addition, the photocatalytic degradation mechanism of the catalyst was explained by free radical scavenging experiment. The material provides an effective method for removing organic pollutants in water, and has broad application prospects.
研究领域:
环境科学
·
材料科学
·
化学工程
·
水处理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）