A high heat of adsorption for hydrogen in magnesium formate.
The hydrogen adsorption and desorption properties of a microporous metal-organic framework, magnesium formate, are investigated. The material has channel-like pores of approximately 3.4 A diameter. The pore size is below the kinetic diameter of nitrogen and causes a breakdown of the linear relationship between maximum hydrogen uptake and specific surface area measured by nitrogen adsorption. From the experimental isotherms the isosteric heat of adsorption for hydrogen is calculated with very high accuracy over a wide range of surface coverage, up to 80 %. The isosteric heat of adsorption is 6.5-7 kJ mol(-1) which is one of the highest values ever observed over the whole range of surface coverage.
Department of Advanced Magnetic Materials, Max Planck Institute for Metals Research, Heisenbergstr. 3, 70569 Stuttgart, Germany.
Barbara
B
Schmitz
Ivana
I
Krkljus
Emi
E
Leung
Hans Wolfgang
HW
Höffken
Ulrich
U
Müller
Michael
M
Hirscher
D000327:Adsorption; D004736:Energy-Generating Resources; D005561:Formates / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D016062:Porosity; D013816:Thermodynamics
D005561:Formates; D006859:Hydrogen; D008274:Magnesium