Nickel Catalyzed Conversion of Activated Carbon into Porous Silicon Carbide

1994 ◽  
Vol 368 ◽  
Author(s):  
R. Moene ◽  
J. Schoonman ◽  
M. Makkee ◽  
J. A. Moulijn

ABSTRACTHigh surface area silicon carbide (SiC) of 31 m2/g has been synthesized by the catalytic conversion of activated carbon. The thermal stability in non-oxidizing environments is shown to be excellent; no significant sintering has been observed after ageing in nitrogen for 4 hours at 1273 K. The presence of 2v% steam or the use of air results in SiC oxidation into SiO2 and considerable sintering at 1273 K. Air oxidation of SiC is shown to cause substantial SiC conversion, viz. 60 % after 10 hours at 1273 K. Complete conversion is achieved at 1080 K in about 100 days. This rate of oxidation agrees with reports on the oxidation of non-porous Acheson SiC and Chemical Vapour Deposited SiC coatings. The use of SiC based catalysts is, therefore, limited to (1) high temperature gas phase reactions operating in the absence of oxidizing constituents (O2 or H2O) and (2) liquid phase processes at demanding pH. Syntheses of highly dispersed and highly loaded Ni/SiC catalysts are feasible by applying an ion-exchange technique, resulting in supported nickel particles of 4 nm.

2012 ◽  
Vol 7 (2_suppl) ◽  
pp. 155892501200702 ◽  
Author(s):  
Juan José Vilatela ◽  
Alan H. Windle

Fibers made up of carbon nanotubes (CNTs) have emerged as a new high-performance material with an exceptional combination of properties derived from those of the CNT building blocks. These fibers can be produced by spinning a CNT aerogel directly from the gas-phase during CNT growth by chemical vapour deposition. The process is continuous and can currently spin fibers at rates of 100m/min. The unique yarn-like structure of CNT fibers gives them exceptional toughness, resilience to bending stresses, extremely high surface area and good integration in polymer matrices. This work shows an overview of the production, properties and prospects of this new high-performance fiber.


1997 ◽  
Vol 162 (1-2) ◽  
pp. 181-191 ◽  
Author(s):  
R. Moene ◽  
L.F. Kramer ◽  
J. Schoonman ◽  
M. Makkee ◽  
J.A. Moulijn

2019 ◽  
Author(s):  
Chem Int

Activated carbon was prepared from molasses, which are natural precursors of vegetable origin resulting from the sugar industry. A simple elaboration process, based on chemical activation with phosphoric acid, was proposed. The final product, prepared by activation of molasses/phosphoric acid mixture in air at 500°C, presented high surface area (more than 1400 m2/g) and important maximum adsorption capacity for methylene blue (625 mg/g) and iodine (1660 mg/g). The activated carbon (MP2(500)) showed a good potential for the adsorption of Cr(VI), Cu(II) and Pb(II) from aqueous solutions. The affinity for the three ions was observed in the following order Cu2+ Cr6+ Pb2+. The process is governed by monolayer adsorption following the Langmuir model, with a correlation coefficient close to unity.


2004 ◽  
Vol 4 (5-6) ◽  
pp. 21-28
Author(s):  
S.-C. Kim ◽  
D.-K. Lee

TiO2-coated granular activated carbon was employed for the removal of toxic microcystin-LR from water. High surface area of the activated carbon provided sites for the adsorption of microcystin-LR, and the adsorbed microcystin-LR migrated continuously onto the surface of TiO2 particles which located mainly at the exterior surface in the vicinity of the entrances of the macropores of the activated carbon. The migrated microcystin-LR was finally degraded into nontoxic products and CO2 very quickly. These combined roles of the activated carbon and TiO2 showed a synergistic effect on the efficient degradation of toxic microcystin-LR. A continuous flow fluidized bed reactor with the TiO2-coated activated carbon could successfully be employed for the efficient photocatalytic of microcystin-LR.


Nanoscale ◽  
2015 ◽  
Vol 7 (25) ◽  
pp. 10974-10981 ◽  
Author(s):  
Xiulin Yang ◽  
Ang-Yu Lu ◽  
Yihan Zhu ◽  
Shixiong Min ◽  
Mohamed Nejib Hedhili ◽  
...  

High surface area FeP nanosheets on a carbon cloth were prepared by gas phase phosphidation of electroplated FeOOH, which exhibit exceptionally high catalytic efficiency and stability for hydrogen generation.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1907
Author(s):  
Fatma Hussain Emamy ◽  
Ali Bumajdad ◽  
Jerzy P. Lukaszewicz

Optimizing the physicochemical properties of the chitosan-based activated carbon (Ch-ACs) can greatly enhance its performance toward heavy metal removal from contaminated water. Herein, Ch was converted into a high surface area (1556 m2/g) and porous (0.69 cm3/g) ACs with large content of nitrogen (~16 wt%) using K2CO3 activator and urea as nitrogen-enrichment agents. The prepared Ch-ACs were tested for the removal of Cr(VI) and Pb(II) at different pH, initial metal ions concentration, time, activated carbon dosage, and temperature. For Cr(VI), the best removal was at pH = 2, while for Pb(II) the best pH for its removal was in the range of 4–6. At 25 °C, the Temkin model gives the best fit for the adsorption of Cr(VI), while the Langmuir model was found to be better for Pb(II) ions. The kinetics of adsorption of both heavy metal ions were found to be well-fitted by a pseudo-second-order model. The findings show that the efficiency and the green properties (availability, recyclability, and cost effectiveness) of the developed adsorbent made it a good candidate for wastewaters treatment. As preliminary work, the prepared sorbent was also tested regarding the removal of heavy metals and other contaminations from real wastewater and the obtained results were found to be promising.


Sign in / Sign up

Export Citation Format

Share Document