HYDROGEN SORPTION ON GRAPHITE AT ELEVATED TEMPERATURES

Journal Article · Thu Sep 01 04:00:00 EDT 1960 · Journal of Physical Chemistry (U.S.)

DOI:https://doi.org/10.1021/j100838a002· OSTI ID:4135520

Redmond, J P; Walker, Jr, P L

S>The sorption of hydrogen on selected types of nuclear and spectroscopic graphite was studied. On nuclear graphite, the desorption of hydrogen over the temperature range 1035 to 1375 deg followed the Elovich equation. The activation energy of desorption over the coverage range ( theta ), 0.32 to 0.68 could be approximated as E' = 137-42( theta ) kcal/mole. On the basis of limited results, it was found that the adsorption of hydrogen at 1335 deg on nuclear graphite could also be expressed by the Elovich equation. Isotherms for sorption of hydrogen on both nuclear and spectroscopic graphites over the temperature range 920 to 1495 deg were of the Temkin type. However, at temperatures of 1085 deg and above, the isotherms consisted of two straightline regions of markedly different slopes. From the isotherms at 1335 and 1495 deg for the nuclear graphite, the heat of adsorption over the coverage range, 0.50 to 0.80, could be approximated as Q = 58--56( theta ) kcal/mole. It was concluded that the adsorption of hydrogen occurred on carbon atoms at the edge of crystallites and that significant intracrystalline sorption did not occur. (auth)

• Research Organization: Pennsylvania State Univ., University Park
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-025483
• OSTI ID: 4135520
• Journal Information: Journal of Physical Chemistry (U.S.), Journal Name: Journal of Physical Chemistry (U.S.) Vol. Vol: 64; ISSN JPCHA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ADSORPTION
CHEMISTRY
ELOVICH EQUATION
EQUATIONS
GRAPHITE
HYDROGEN
TEMPERATURE