scholarly journals Selective Hydrogenation of the Carbonyls in Furfural and 5-Hydroxymethylfurfural Catalyzed by PtNi Alloy Supported on SBA-15 in Aqueous Solution Under Mild Conditions

2021 ◽  
Vol 9 ◽  
Author(s):  
Ge Gao ◽  
Zhicheng Jiang ◽  
Changwei Hu
Keyword(s):  
Selective Hydrogenation ◽  
Water Resistance ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
High Dispersion ◽  
Atom Economy ◽  
Water Solvent ◽  
Ordered Mesoporous ◽  
Ptni Alloy

Valuable furfuryl alcohol (FFA) and 2,5-dihydroxymethylfuran (DHMF) could be produced by selective hydrogenation of biomass-derived furfural (FF) and 5-hydroxymethylfurfural (HMF) with high atom economy. In this study, SBA-15 (a kind of mesoporous silica molecular sieve)-supported low metal loading (3 wt% total metal content) PtNi alloy catalyst (PtNi/SBA-15) was synthesized via two steps, including the generation of PtNi alloy by hydrothermal method, and the immobilization of PtNi alloy on SBA-15. PtNi/SBA-15 has ordered mesoporous structure with high surface area, and high dispersion of the PtNi alloy with the formation of Ptδ−-Niδ+ surface pairs on SBA-15, which benefit hydrogen activation and selective carbonyl hydrogenation. The selective hydrogenation of FF and HMF over PtNi/SBA-15 in water solvent at 303 K with 1.5 MPa H2 within 2 h, could respectively yield 64.6% FFA with 77.0% selectivity, and 68.2% DHMF with 81.9% selectivity. Besides, PtNi/SBA-15 exhibited a satisfactory water resistance and stability after recycling at least five runs.

Iron Disulfide Cathode Material Incorporated in Highly Ordered Mesoporous Carbon for Rechargeable Lithium Ion Batteries

2020 ◽  
Vol 12 (9) ◽  
pp. 1265-1270
Author(s):  
Ying Liu ◽  
Jungwon Heo ◽  
Xueying Li ◽  
Yuanzheng Sun ◽  
Younki Lee ◽  
...  
Keyword(s):  
Mesoporous Carbon ◽  
High Surface ◽  
Active Material ◽  
High Surface Area ◽  
Lithium Ion ◽  
Mesoporous Structure ◽  
Ordered Mesoporous Carbon ◽  
Iron Disulfide ◽  
Excellent Electrochemical Performance ◽  
Ordered Mesoporous

A highly ordered mesoporous carbon@iron disulfide (CMK-5@FeS2) composite was prepared via an in-situ impregnation and sulfurization method. The CMK-5 matrix with excellent conductivity and high surface area not only formed a continuous conductive network to improve the performance of the CMK-5@FeS2 composite, but also provided sufficient space to buffer the volume changes during cycling. The CMK-5@FeS2 cell exhibited excellent electrochemical performance. After 80 cycles, the CMK-5@FeS2 cell showed the discharge capacities of 650 and 380 mAh g–1 at 2 C and 5 C, respectively. The excellent results show that CMK-5 with unique mesoporous structure can contribute to accelerating ion transfer in the electrode due to the easy accessibility of the electrolyte, which implies CMK-5@FeS2 composite could be a promising cathode active material for rechargeable lithium ion (Li-ion) batteries.

SYNTHESIS OF WORMLIKE NANOPOROUS NICKEL OXIDE WITH NANOCRYSTALLINE FRAMEWORK FOR ELECTROCHEMICAL ENERGY STORAGE

2004 ◽  
Vol 03 (03) ◽  
pp. 321-329 ◽  
Author(s):  
WEI XING ◽  
FENG LI ◽  
ZI F. YAN ◽  
H. M. CHENG ◽  
GAO Q. LU
Keyword(s):  
Nickel Oxide ◽  
High Surface ◽  
Sodium Dodecyl ◽  
High Surface Area ◽  
Pore Wall ◽  
High Specific Capacitance ◽  
Mesoporous Structure ◽  
Nanoporous Structure ◽  
Assembly Method ◽  
Ordered Mesoporous

In this work, nanoporous nickel oxide was synthesized using anionic surfactant assembly method. Structure characterizations show that this nickel oxide possesses partly-ordered mesoporous structure with nanocrystalline pore wall. The formation mechanism of wormlike nanoporous structure is ascribed to the quasi-reverse micelle system formed by ternary phases of SDS (sodium dodecyl sulfate)/urea/water. Cyclic voltammetry shows that these nickel oxide samples possess both good capacitive behavior due to its unique nanoporous structure and very high specific capacitance due to its high surface area with electrochemical activity.

Surface Functionalization of Ordered Mesoporous Carbon by Immobilization of Diamine for Cobalt-Ion Adsorption

2014 ◽  
Vol 602-603 ◽  
pp. 300-303 ◽  
Author(s):  
Shu Ya Geng ◽  
Li Min Dong ◽  
Chen Wang ◽  
Tong Xiang Liang
Keyword(s):  
Surface Functionalization ◽  
Mesoporous Carbon ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Adsorption Properties ◽  
Ordered Mesoporous Carbon ◽  
Ion Adsorption ◽  
Ordered Mesoporous ◽  
Adsorption Of Co

Highly ordered mesoporous carbon (CMK-3) was fabricated for the adsorption of cobalt from aqueous solutions. With the high surface area of1112.7m2/g and pore size of 17.2 nm, its abundant mesopores were benefit for providing channels for liquid propagate. In order to improve the adsorption properties,CMK-3 was modified by hydroxylation and amination. Fourier transform infrared (FTIR) spectroscopy can be seen that the amino group was successfully grafted onto the CMK-3 with highly ordered mesoporous structure. The functionalized ordered mesoporous carbon (CMK-3-EDA) ,CMK-3 and CMK-3-OX were used as absents for the adsorption of Co (II) from aqueous solution. The results showed that CMK-3-EDA were more twice effective in adsorption of Co (II) compared to CMK-3, which indicated that CMK-3-EDA had great potential for the adsorption of Co (II).

Hard-templating synthesis and enhanced photocatalysis of mesoporous titanium dioxides nanoparticles

2018 ◽  
Vol 11 (04) ◽  
pp. 1850077 ◽  
Author(s):  
K. L. Jin ◽  
X. J. Chen ◽  
J. C. Xu ◽  
Y. S. Huang ◽  
Y. B. Han ◽  
...  
Keyword(s):  
Surface Area ◽  
Anatase Phase ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Photocatalytic Decomposition ◽  
Titanium Dioxides ◽  
Decomposition Efficiency ◽  
Templating Synthesis ◽  
Mb Adsorption

Mesoporous titanium dioxides nanoparticles (TiO2 NPs) were synthesized using activated carbon (AC) as templates after the decomposition of AC. All results indicated that TiO2 NPs with the small grain size presented the anatase phase structure. Mesoporous TiO2 NPs showed the high surface area and the surface area decreased with the TiO2 content. The removal of methylene blue (MB) indicated that the photocatalytic decomposition efficiency of mesoporous TiO2 NPs increased up to 92% for three-times doping with the TiO2 content, and then decreased. This should be attributed to the synergistic effect from the MB adsorption of mesoporous-structure and the photocatalysis of TiO2 NPs. Therefore, the higher MB concentration near TiO2 NPs from the mesoporous-structure increased the touch chance and the MB photocatalytic decomposition was promoted greatly.

Defect Chemistry of Oxide Nanomaterials with High Surface Area: Ordered Mesoporous Thin Films of the Oxygen Storage Catalyst CeO2–ZrO2

ACS Nano ◽  
2013 ◽  
Vol 7 (4) ◽  
pp. 2999-3013 ◽  
Author(s):  
Pascal Hartmann ◽  
Torsten Brezesinski ◽  
Joachim Sann ◽  
Andriy Lotnyk ◽  
Jens-Peter Eufinger ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Defect Chemistry ◽  
Oxygen Storage ◽  
Ordered Mesoporous ◽  
Mesoporous Thin Films ◽  
Storage Catalyst

scholarly journals Characterization of Residual Biomasses and Its Application for the Removal of Lead Ions from Aqueous Solution

2019 ◽  
Vol 9 (21) ◽  
pp. 4486 ◽  
Author(s):  
Candelaria Tejada-Tovar ◽  
Angel Darío Gonzalez-Delgado ◽  
Angel Villabona-Ortiz
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Mesoporous Structure ◽  
Isotherm Models ◽  
Solution Ph ◽  
Batch Mode ◽  
Suitable Alternative

The removal of water pollutants has been widely addressed for the conservation of the environment, and novel materials are being developed as adsorbent to address this issue. In this work, different residual biomasses were employed to prepare biosorbents applied to lead (Pb(II)) ion uptake. The choice of cassava peels (CP), banana peels (BP), yam peels (YP), and oil palm bagasse (OPB) was made due to the availability of such biomasses in the Department of Bolivar (Colombia), derived from agro-industrial activities. The materials were characterized by ultimate and proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) in order to determine the physicochemical properties of bioadsorbents. The adsorption tests were carried out in batch mode, keeping the initial metal concentration at 100 ppm, temperature at 30 °C, particle size at 1 mm, and solution pH at 6. The experimental results were adjusted to kinetic and isotherm models to determine the adsorption mechanism. The remaining concentration of Pb(II) in solution was measured by atomic absorption at 217 nm. The functional groups identified in FTIR spectra are characteristic of lignocellulosic materials. A high surface area was found for all biomaterials with the exception of yam peels. A low pore volume and size, related to the mesoporous structure of these materials, make these bioadsorbents a suitable alternative for liquid phase adsorption, since they facilitate the diffusion of Pb(II) ions onto the adsorbent structure. Both FTIR and EDS techniques confirmed ion precipitation onto adsorbent materials after the adsorption process. The adsorption tests reported efficiency values above 80% for YP, BP, and CP, indicating a good uptake of Pb(II) ions from aqueous solution. The results reported that Freundlich isotherm and pseudo-second order best fit experimental data, suggesting that the adsorption process is governed by chemical reactions and multilayer uptake. The future prospective of this work lies in the identification of alternatives to reuse Pb(II)-contaminated biomasses after heavy metal adsorption, such as material immobilization.

Synthesis and capacitive properties of carbonaceous sphere@MnO2 rattle-type hollow structures

2010 ◽  
Vol 25 (8) ◽  
pp. 1476-1484 ◽  
Author(s):  
Jintao Zhang ◽  
Jizhen Ma ◽  
Jianwen Jiang ◽  
X.S. Zhao
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Experimental Conditions ◽  
X Ray ◽  
Hollow Structures ◽  
Capacitive Properties

Carbonaceous sphere@MnO2 rattle-type hollow spheres were synthesized under mild experimental conditions. The as-prepared hollow structures were characterized using scanning electron microscope, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and nitrogen adsorption techniques. The characterization data showed the formation of rattle-type hollow structures with a mesoporous MnO2 shell and a carbonaceous sphere core. The composition and shell thickness of the hollow spheres can be controlled experimentally. The capacitive performance of the hollow structures was evaluated by using both cycle voltammetry and charge–discharge methods. The results demonstrated a specific capacitance as high as 184 F/g at a current density of 125 mA/g. The good electrocapacitive performance resulted from the mesoporous structure and high surface area of the MnO2-based hollow spheres.

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