scholarly journals A Systematic Study on Bio-Based Hybrid Aerogels Made of Tannin and Silica

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5231
Author(s):  
Ann-Kathrin Koopmann ◽  
Wim J. Malfait ◽  
Thomas Sepperer ◽  
Nicola Huesing
Keyword(s):  
Specific Surface ◽  
Processing Parameters ◽  
Water Soluble ◽  
High Porosity ◽  
Mesopore Volume ◽  
One Pot ◽  
Surface Areas ◽  
Hybrid Aerogels ◽  
Highly Porous ◽  
Silica Hybrid

Tannin-silica hybrid materials are expected to feature excellent mechanic-chemical stability, large surface areas, high porosity and possess, after carbothermal reduction, high thermal stability as well as high thermal conductivity. Typically, a commercially available tetraethoxysilane is used, but in this study, a more sustainable route was developed by using a glycol-based silica precursor, tetrakis(2-hydroxyethyl)orthosilicate (EGMS), which is highly water-soluble. In order to produce highly porous, homogeneous hybrid tannin-silica aerogels in a one-pot approach, a suitable crosslinker has to be used. It was found that an aldehyde-functionalized silane (triethoxysilylbutyraldehyde) enables the covalent bonding of tannin and silica. Solely by altering the processing parameters, distinctly different tannin-silica hybrid material properties could be achieved. In particular, the amount of crosslinker is a significant factor with respect to altering the materials’ properties, e.g., the specific surface area. Notably, 5 wt% of crosslinker presents an optimal percentage to obtain a sustainable tannin-silica hybrid system with high specific surface areas of roughly 800–900 m2 g−1 as well as a high mesopore volume. The synthesized tannin-silica hybrid aerogels permit the usage as green precursor for silicon carbide materials.

Biomass based nitrogen-doped structure-tunable versatile porous carbon materials

2017 ◽  
Vol 5 (25) ◽  
pp. 12958-12968 ◽  
Author(s):  
Xin Zhou ◽  
Penglei Wang ◽  
Yagang Zhang ◽  
Lulu Wang ◽  
Letao Zhang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Porous Carbon ◽  
Carbon Materials ◽  
Porous Carbons ◽  
One Pot ◽  
Nitrogen Doped ◽  
Porous Carbon Materials ◽  
Surface Areas ◽  
Cellulose Carbamate ◽  
Specific Surface Areas

Hierarchical nitrogen-doped porous carbons (HNPCs) with tunable pore structures and ultrahigh specific surface areas were designed and prepared from sustainable biomass precursor cellulose carbamate via simultaneous carbonization and activation by a facile one-pot approach.

Balancing volumetric and gravimetric uptake in highly porous materials for clean energy

Science ◽  
2020 ◽  
Vol 368 (6488) ◽  
pp. 297-303 ◽  
Author(s):  
Zhijie Chen ◽  
Penghao Li ◽  
Ryther Anderson ◽  
Xingjie Wang ◽  
Xuan Zhang ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Clean Energy ◽  
Department Of Energy ◽  
High Porosity ◽  
Surface Areas ◽  
Metal Organic ◽  
Trinuclear Clusters ◽  
Temperature And Pressure ◽  
Pressure Swing ◽  
Highly Porous

A huge challenge facing scientists is the development of adsorbent materials that exhibit ultrahigh porosity but maintain balance between gravimetric and volumetric surface areas for the onboard storage of hydrogen and methane gas—alternatives to conventional fossil fuels. Here we report the simulation-motivated synthesis of ultraporous metal–organic frameworks (MOFs) based on metal trinuclear clusters, namely, NU-1501-M (M = Al or Fe). Relative to other ultraporous MOFs, NU-1501-Al exhibits concurrently a high gravimetric Brunauer−Emmett−Teller (BET) area of 7310 m2 g−1 and a volumetric BET area of 2060 m2 cm−3 while satisfying the four BET consistency criteria. The high porosity and surface area of this MOF yielded impressive gravimetric and volumetric storage performances for hydrogen and methane: NU-1501-Al surpasses the gravimetric methane storage U.S. Department of Energy target (0.5 g g−1) with an uptake of 0.66 g g−1 [262 cm3 (standard temperature and pressure, STP) cm−3] at 100 bar/270 K and a 5- to 100-bar working capacity of 0.60 g g−1 [238 cm3 (STP) cm−3] at 270 K; it also shows one of the best deliverable hydrogen capacities (14.0 weight %, 46.2 g liter−1) under a combined temperature and pressure swing (77 K/100 bar → 160 K/5 bar).

scholarly journals Combustion-Synthesized Porous CuO-CeO2-SiO2 Composites as Solid Catalysts for the Alkenylation of C(sp3)-H Bonds Adjacent to a Heteroatom via Cross-Dehydrogenative Coupling

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1252
Author(s):  
Ha V. Le ◽  
Vy B. Nguyen ◽  
Hai H. Pham ◽  
Khoa D. Nguyen ◽  
Phuoc H. Ho ◽  
...  
Keyword(s):  
Mixed Oxides ◽  
Coupling Reaction ◽  
Catalytic Performance ◽  
Composite Catalyst ◽  
High Porosity ◽  
One Pot ◽  
General Validity ◽  
Solid Catalysts ◽  
Surface Areas ◽  
Dehydrogenative Coupling

A series of mixed oxides of CuO, CeO2, and SiO2 were prepared by gel combustion and employed for the first time as efficient solid catalysts in a solvent-less liquid-phase cross-dehydrogenative coupling. The facile one-pot catalyst synthesis resulted in highly porous materials presenting large specific surface areas and strong metal–support interactions. The interaction with highly dispersed CeO2 enhanced the redox properties of the CuO species. The CuO-CeO2-SiO2 composites exhibited excellent catalytic performance for the selective coupling between 1,1-diphenylethylene and tetrahydrofuran with a yield up to 85% of 2-(2,2-diphenylvinyl)-tetrahydrofuran in the presence of di-tert-butyl peroxide (DTPB) and KI. Albeit both CuO and CeO2 species are proved to be responsible for the catalytic conversion, a great synergistic improvement in the catalytic activity was obtained by extended contact between the oxide phases by high porosity in comparison with the reactions using individual Cu or Ce catalysts. The activity of the composite catalyst was shown to be highly stable after five successive reaction cycles. Furthermore, the study scope was extended to the synthesis of different derivatives via composite-catalyzed coupling of C(sp2)-H with C(sp3-H) adjacent to a heteroatom. The good yields recorded proved the general validity of this composite for the cross-dehydrogenative coupling reaction rarely performed on solid catalysts.

scholarly journals One-Pot, Room-Temperature Conversion of CO2 into Porous Metal−Organic Frameworks

2020 ◽  
Author(s):  
Kentaro Kadota ◽  
You-Lee Hong ◽  
Yusuke Nishiyama ◽  
Easan Sivaniah ◽  
Daniel Packwood ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
One Pot ◽  
Surface Areas ◽  
Piperazine Derivatives ◽  
Metal Organic ◽  
The One ◽  
Crystalline Metal ◽  
Highly Porous

We demonstrate the one-pot synthesis of highly porous crystalline metal−organic frameworks, [Zn<sub>4</sub>O(piperazine dicarbamate)<sub>3</sub>], an analogue of [Zn<sub>4</sub>O(1,4-benzenedicarboxylate)<sub>3</sub>] (MOF-5), directly from atmospheric pressure CO<sub>2</sub> gas and piperazine derivatives at 25 °C. The structures showed high CO<sub>2</sub> contents over 30 wt% and surface areas of 1270−2366 m<sup>2</sup> g<sup>−1</sup>. We also show that the synthesis is feasible even by the use of 400 ppm of CO<sub>2</sub>.

Niobium and Antimony-Modified Titanium Dioxide/Epoxy Thin Film for Proton Exchange Membrane Fuel Cell

2008 ◽  
Vol 55-57 ◽  
pp. 621-624
Author(s):  
Tanita Kuanchaitrakul ◽  
S. Chirachanchai ◽  
H. Manuspiya
Keyword(s):  
Fuel Cell ◽  
Specific Surface ◽  
Proton Exchange Membrane ◽  
Pure Tio2 ◽  
Proton Exchange ◽  
High Porosity ◽  
Doped Tio2 ◽  
Fuel Cell Performance ◽  
Surface Areas ◽  
Exchange Membrane

Inorganic Mesoporous Membrane is a new alternative to improve high-temperature fuel cell performance in proton exchange membrane fuel cells (PEMFCs) to substitute for Nafion. It possess high porosity and high specific surface areas, resulting in high proton conductivity. In this study, niobium-modified titania and antimony/niobium-modified titania ceramic were prepared via the sol-gel technique. The various contents of antimony, 0 to 3 wt%, and 3% niobium are incorporated into titania to improve the porous surface condition of the ceramic particles. The xerogels were heated at about 500°C. Inorganic membranes were prepared by using the spin-coating technique using epoxy resin as a binder. The physical, chemical, and electrical properties of these membranes were investigated. The XRD and Raman results showed that pure TiO2 and doped TiO2 nanoparticles obtained possess an anatase structure with mesoporosity. The specific surface area of the doped TiO2 was higher than that of pure TiO2 and it is worth pointing out that the doping of antimony affected the surface areas more than the doping of niobium in TiO2. Moreover, these membranes were also tested to evaluate their potential use as an electrolyte in PEMFC by using impedance spectroscopy, TGA, mechanical properties and water uptake.

scholarly journals One-Pot, Room-Temperature Conversion of CO2 into Porous Metal−Organic Frameworks

2020 ◽  
Author(s):  
Kentaro Kadota ◽  
You-Lee Hong ◽  
Yusuke Nishiyama ◽  
Easan Sivaniah ◽  
Daniel Packwood ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
One Pot ◽  
Surface Areas ◽  
Piperazine Derivatives ◽  
Metal Organic ◽  
The One ◽  
Crystalline Metal ◽  
Highly Porous

We demonstrate the one-pot synthesis of highly porous crystalline metal−organic frameworks, [Zn<sub>4</sub>O(piperazine dicarbamate)<sub>3</sub>], an analogue of [Zn<sub>4</sub>O(1,4-benzenedicarboxylate)<sub>3</sub>] (MOF-5), directly from atmospheric pressure CO<sub>2</sub> gas and piperazine derivatives at 25 °C. The structures showed high CO<sub>2</sub> contents over 30 wt% and surface areas of 1270−2366 m<sup>2</sup> g<sup>−1</sup>. We also show that the synthesis is feasible even by the use of 400 ppm of CO<sub>2</sub>.

scholarly journals Highly Porous Au–Pt Bimetallic Urchin-Like Nanocrystals for Efficient Electrochemical Methanol Oxidation

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 112
Author(s):  
Heon Chul Kim ◽  
Jong Wook Hong
Keyword(s):  
Methanol Oxidation ◽  
Active Sites ◽  
Synthesis Method ◽  
High Porosity ◽  
One Pot ◽  
Wet Chemical Synthesis ◽  
Bimetallic Nanocrystals ◽  
Wet Chemical ◽  
Surface Active ◽  
Highly Porous

Highly porous Au–Pt urchin-like bimetallic nanocrystals have been prepared by a one-pot wet-chemical synthesis method. The porosity of urchin-like bimetallic nanocrystals was controlled by amounts of hydrazine used as reductant. The prepared highly porous Au-Pt urchin-like nanocrystals were superior catalysts of electrochemical methanol oxidation due to high porosity and surface active sites by their unique morphology. This approach will pave the way for the design of bimetallic porous materials with unprecedented functions.

scholarly journals Carbon/silica hybrid aerogels with controlled porosity by a quick one-pot synthesis

2021 ◽  
Vol 569 ◽  
pp. 120992
Author(s):  
Samantha L. Flores-López ◽  
Miguel A. Montes-Morán ◽  
Ana Arenillas
Keyword(s):  
One Pot ◽  
One Pot Synthesis ◽  
Controlled Porosity ◽  
Hybrid Aerogels ◽  
Silica Hybrid

Inorganic Mesoporous Membrane for Potentially Used in Proton Exchange Membrane

2008 ◽  
Vol 54 ◽  
pp. 311-316
Author(s):  
Tanita Kuanchaitrakul ◽  
S. Chirachanchai ◽  
H. Manuspiya
Keyword(s):  
Specific Surface ◽  
Proton Exchange Membrane ◽  
Pure Tio2 ◽  
Proton Exchange ◽  
High Porosity ◽  
Doped Tio2 ◽  
Fuel Cell Performance ◽  
Surface Areas ◽  
Exchange Membrane ◽  
Mesoporous Membrane

Inorganic Mesoporous Membrane is a new alternative to improve high-temperature fuel cell performance in proton exchange membrane fuel cells (PEMFCs) to substitute for Nafion. It possess high porosity and high specific surface areas, resulting in high proton conductivity. In this study, niobium-modified titania and antimony/niobium-modified titania ceramic were prepared via the sol-gel technique. The various contents of antimony, 0 to 3 wt%, and 3% niobium are incorporated into titania to improve the porous surface condition of the ceramic particles. The xerogels were heated at about 500°C. Inorganic membranes were prepared by using the spin-coating technique using epoxy resin as a binder. The physical, chemical, and electrical properties of these membranes were investigated. The XRD and Raman results showed that pure TiO2 and doped TiO2 nanoparticles obtained possess an anatase structure with mesoporosity. The specific surface area of the doped TiO2 was higher than that of pure TiO2 and it is worth pointing out that the doping of antimony affected the surface areas more than the doping of niobium in TiO2. Moreover, these membranes were also tested to evaluate their potential use as an electrolyte in PEMFC by using impedance spectroscopy, TGA, mechanical properties and water uptake.

scholarly journals Simultaneous Adsorption and Reduction of Cr(VI) to Cr(III) in Aqueous Solution Using Nitrogen-Rich Aminal Linked Porous Organic Polymers

2021 ◽  
Vol 13 (2) ◽  
pp. 923
Author(s):  
Muhammad A. Sabri ◽  
Ziad Sara ◽  
Mohammad H. Al-Sayah ◽  
Taleb H. Ibrahim ◽  
Mustafa I. Khamis ◽  
...  
Keyword(s):  
Active Sites ◽  
Condensation Reaction ◽  
Significant Loss ◽  
Single Step ◽  
High Porosity ◽  
Organic Polymers ◽  
Porous Organic Polymers ◽  
One Pot ◽  
Surface Areas ◽  
Redox Active

Two novel nitrogen-rich aminal linked porous organic polymers, NRAPOP-O and NRAPOP-S, have been prepared using a single step-one pot Schiff-base condensation reaction of 9,10-bis-(4,6-diamino-S-triazin-2-yl)benzene and 2-furaldehyde or 2-thiophenecarboxaldehyde, respectively. The two polymers show excellent thermal and physiochemical stabilities and possess high porosity with Brunauer–Emmett–Teller (BET) surface areas of 692 and 803 m2 g−1 for NRAPOP-O and NRAPOP-S, respectively. Because of such porosity, attractive chemical and physical properties, and the availability of redox-active sites and physical environment, the NRAPOPs were able to effectively remove Cr(VI) from solution, reduce it to Cr(III), and simultaneously release it into the solution. The efficiency of the adsorption process was assessed under various influencing factors such as pH, contact time, polymer dosage, and initial concentration of Cr(VI). At the optimum conditions, 100% removal of Cr(VI) was achieved, with simultaneous reduction and release of Cr(III) by NRAPOP-O with 80% efficiency. Moreover, the polymers can be easily regenerated by the addition of reducing agents such as hydrazine without significant loss in the detoxication of Cr(VI).

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