Hydrogen Adsorption on Activated Carbon an Carbon Nanotubes Using Volumetric Differential Pressure Technique

Journal Article · Thu Mar 11 00:00:00 EST 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3377873· OSTI ID:21371692

Sanip, S M; Saidin, M A. R.; Aziz, M; Ismail, A F ^[1]

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1. Membrane Research Unit, Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor (Malaysia)

A simple hydrogen adsorption measurement system utilizing the volumetric differential pressure technique has been designed, fabricated and calibrated. Hydrogen adsorption measurements have been carried out at temperatures 298 K and 77 K on activate carbon and carbon nanotubes with different surface areas. The adsorption data obtained will be helpful in understanding the adsorption property of the studied carbon materials using the fundamentals of adsorption theory. The principle of the system follows the Sievert-type method. The system measures a change in pressure between the reference cell, R1 and the sample cell S1, S2, S3 over a certain temperature range, R1, S1, S2, and S3 having known fixed volume. The sample temperatures will be monitored by thermocouple TC while the pressures in R1 an S1, S2, S3 will be measured using a digital pressure transducer. The maximum operating pressure of the pressure transducer is 20 bar and calibrated with an accuracy of +-0.01 bar. High purity hydrogen is being used in the system and the amount of samples for the study is between 1.0-2.0 grams. The system was calibrated using helium gas without any samples in S1, S2 an S3. This will provide a correction factor during the adsorption process providing an adsorption free reference point when using hydrogen gas resulting in a more accurate reading of the adsorption process by eliminating the errors caused by temperature expansion effects and other non-adsorption related phenomena. The ideal gas equation of state is applied to calculate the hydrogen adsorption capacity based on the differential pressure measurements. Activated carbon with a surface area of 644.87 m{sup 2}/g showed a larger amount of adsorption as compared to multiwalled nanotubes (commercial) with a surface area of 119.68 m{sup 2}/g. This study als indicated that there is a direct correlation between the amounts of hydrogen adsorbed an surface area of the carbon materials under the conditions studied and that the adsorption significant at 77 K.

• OSTI ID: 21371692
• Journal Information: AIP Conference Proceedings, Vol. 1217, Issue 1; Conference: ICAMN-2007: International conference on advancement of materials and nanotechnology, Langkawi, Kedah (Malaysia), 29 May - 1 Jun 2007; Other Information: DOI: 10.1063/1.3377873; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ACTIVATED CARBON
ADSORPTION
CORRELATIONS
EQUATIONS OF STATE
HELIUM
HYDROGEN
IMPURITIES
NANOTUBES
PRESSURE MEASUREMENT
SURFACE AREA
TEMPERATURE DEPENDENCE
TRANSDUCERS
ADSORBENTS
CARBON
ELEMENTS
EQUATIONS
FLUIDS
GASES
NANOSTRUCTURES
NONMETALS
RARE GASES
SORPTION
SURFACE PROPERTIES