Mechanisms on formation of hierarchically porous carbon and its adsorption behaviors

2016 ◽  
Vol 74 (1) ◽  
pp. 266-275 ◽  
Author(s):  
Jie Liu ◽  
Lingxia Hao ◽  
Wenzhen Qian ◽  
Yu-Feng He ◽  
Rong-Min Wang
Keyword(s):  
Activated Carbon ◽  
Electron Microscope ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Hierarchically Porous ◽  
Adsorption Behaviors

Using simple one-step carbonization-activation, the residues of paulownia flowers are employed as a precursor to prepare hierarchically porous activated carbon. After investigating the optimum conditions, the obtained paulownia flowers based activated carbon (PFAC) is characterized by Fourier transform infrared spectroscopy, scanning electron microscope, transmission electron microscope, Brunauer–Emmett–Teller specific surface area analysis (SBET), thermo gravimetric analysis, and X-ray photoelectron spectroscopy. The PFAC owns a high specific surface area of 1,053 m2/g as well as a hierarchically porous structure with a combination of micro-, meso- and macropores. The pore-forming mechanism is discussed according to results of characterization. Using methylene blue as model dye, the adsorption behaviors of PFAC were investigated. We found that the dye could be rapidly adsorbed by hierarchically porous PFAC, and the adsorption capacity of PFAC reached 300 mg/g.

Structure and Catalytic Soot Combustion of Perovskite La-Mn-O Hollow Microfibers via Gel-Precursor Transformation Process

2012 ◽  
Vol 538-541 ◽  
pp. 2289-2292
Author(s):  
Xiao Xiao Meng ◽  
Feng Lin He ◽  
Jiang Ying Shen ◽  
Xiang Qian Shen
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Surface ◽  
Thermo Gravimetric Analysis ◽  
Transformation Process ◽  
High Catalytic Activity ◽  
Gravimetric Analysis ◽  
Soot Combustion ◽  
Aspect Ratios

The nanocrystalline perovskite La-Mn-O hollow microfibers were prepared by the gel-precursor transformation process from reagents of metal salts and citric acid. The gel precursor and resultant products were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The specific surface area was measured by the Brunauere-Emmette-Teller method. The catalytic performance of soot combustion was evaluated by thermo-gravimetric analysis under model conditions. The nanocrystalline La-Mn-O hollow microfibers calcined at 650 °C for 6 h are characterized with diameters of 2-8 µm, aspect ratios (length/diameter) about 5-15, a micro-tunnel with an estimated ratio 1/3 of the hollow diameter to fiber diameter, and a high specific surface area of 36.7 m2/g that is 1.9 times higher than the counterpart nanosized powder. This nanocrystalline La-Mn-O hollow microfibers catalyst exhibit a high catalytic activity for the soot combustion, with a low T50 of 397°C, which is largely owing to the high surface area and the micro-tunnel structure.

Microstructural properties and pozzolanic activity of calcined kaolins as supplementary cementing materials

2012 ◽  
Vol 39 (12) ◽  
pp. 1274-1284 ◽  
Author(s):  
Erhan Güneyisi ◽  
Mehmet Gesoǧlu ◽  
Turan Özturan ◽  
Kasım Mermerdaş
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Thermo Gravimetric Analysis ◽  
Particle Size Analysis ◽  
Pozzolanic Activity ◽  
Area Measurement ◽  
Size Analysis ◽  
Gravimetric Analysis

In this study, the utilization of unprocessed kaolins calcined at various temperatures as supplementary cementing material was investigated experimentally. The current work deals with four kaolin deposits existing in the western region of Turkey that have not yet been investigated for this purpose. Thermal properties of the unprocessed kaolins were examined by means of differential thermal and thermo gravimetric analysis. After determination of the thermal behavior, pozzolanic activity indices of the kaolins were determined according to ASTM C311. Based on the pozzolanic activity test results, calcination temperatures were assigned for kaolins and the changes in the mineralogical composition and the formation of amorphous structures were examined by X-ray diffraction analysis. The changes in particle size and specific surface area of the calcined kaolin minerals were observed through, particle size analysis with laser diffractometer, Scanning electron microscopy image analysis, and Brunauer-Emmett-Teller specific surface area measurement. The results showed that a complete kaolinite to metakaolinite conversion was achieved by the calcination procedure adopted.

The Synthesis of Pseudoboehmite Using Factorial Experimental Design

2015 ◽  
Vol 365 ◽  
pp. 226-231 ◽  
Author(s):  
Antonio Hortêncio Munhoz ◽  
T.J. Masson ◽  
Leila Figueiredo de Miranda ◽  
A. Cabral Neto ◽  
Raphael Cons Andrades ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ageing Time ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Precursor Solution ◽  
High Specific Surface Area ◽  
Gravimetric Analysis

Different samples of pseudoboehmite were synthesized through the sol-gel process, using aluminum nitrate as precursor. The influence of variables on the product of the synthesis of pseudoboehmite was studied. The variables were the ageing temperature (25 and 130°C), addition or not of polyvinyl alcohol to the precursor solution and the ageing time of the PB. The pH adjustment of the precursor solution was made by using ammonium carbonate. The pseudoboehmites, which were obtained on different conditions, were then characterized by X-ray diffraction, thermal analysis (Differential Thermal Analysis and Thermo Gravimetric Analysis) and the desorption-absorption curves were obtained as well, in order to measure the pore volume of the samples and the specific surface area measurements through the BET method. Finally, the results were analyzed through an experimental factorial planning, which showed that high specific surface area pseudoboehmite was obtained.

scholarly journals Experimental Study on Activated Carbon-MIL-101(Cr) Composites for Ethanol Vapor Adsorption

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3811
Author(s):  
Zhongbao Liu ◽  
Jiayang Gao ◽  
Xin Qi ◽  
Zhi Zhao ◽  
Han Sun
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Ethanol Vapor ◽  
Future Application ◽  
Working Fluid ◽  
Relative Pressure ◽  
Adsorption Refrigeration ◽  
Vapor Adsorption

In this study, the hydrothermal method was used to synthesize MIL-101(Cr), and activated carbon (AC) with different content was incorporated in to MIL-101(Cr), thereby obtaining AC-MIL-101(Cr) composite material with a huge specific surface area. The physical properties of MIL-101(Cr) and AC-MIL-101(Cr) were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), nitrogen adsorption and desorption and specific surface area testing, and ethanol vapor adsorption performance testing. The results show that with the increase of activated carbon content, the thermal stability of AC-MIL-101(Cr) is improved. Compared with the pure sample, the BET specific surface area and pore volume of AC-MIL-101(Cr) have increased; In the relative pressure range of 0–0.4, the saturated adsorption capacity of AC-MIL-101(Cr) to ethanol vapor decreases slightly. It is lower than MIL-101(Cr), but its adsorption rate is improved. Therefore, AC-MIL-101(Cr)/ethanol vapor has a good application prospect in adsorption refrigeration systems. The exploration of AC-MIL-101(Cr) composite materials in this paper provides a reference for the future application of carbon-based/MOFS composite adsorbent/ethanol vapor working fluid in adsorption refrigeration.

Increase the Microporosity and CO2 Adsorption of a Commercial Activated Carbon

2015 ◽  
Vol 749 ◽  
pp. 17-21 ◽  
Author(s):  
Joanna Sreńscek Nazzal ◽  
Karolina Glonek ◽  
Jacek Młodzik ◽  
Urszula Narkiewicz ◽  
Antoni W. Morawski ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials ◽  
Micropore Volume ◽  
Microporous Carbon ◽  
Microporous Carbons ◽  
Adsorption Capacities

Microporous carbons prepared from commercial activated carbon WG12 by KOH and/or ZnCl2 treatment were examined as adsorbents for CO2 capture. The micropore volume and specific surface area of the resulting carbons varied from 0.52 cm3/g (1374 m2/g) to 0.70 cm3/g (1800 m2/g), respectively. The obtained microporous carbon materials showed high CO2 adsorption capacities at 40 bar pressure reaching 16.4 mmol/g.

Study of the Porous Structure and High Adsorption Capacity of Biomass-Based Activated Carbon Prepared from Aspen Wood by Ferric Nitrate III Activation

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Mass Ratio ◽  
Aspen Wood ◽  
Surface Functional Groups ◽  
Wood Sawdust

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.

Mesoporous Activated Carbon Filaments

1996 ◽  
Vol 454 ◽  
Author(s):  
Weiming Lu ◽  
D. D. L. Chung
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mesoporous Activated Carbon ◽  
Carbon Filaments

ABSTRACTActivated carbon filaments of diameter ∼0.1 μm, main pore size (BJH) 55 Å, specific surface area 1310 m2/g and yield 36.2% were obtained by activating carbon filaments of diameter ∼ 0.1 urn in C02 + N2 (1:1) at 970°C for 80 min. Prior to this activation, the filaments were surface oxidized by exposure to ozone.

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