Carbon monoxide adsorption equilibria and kinetics on zeolite 5A, 13X, MOF-5, and MOF-177 were measured volumetrically at 298, 237 and 194.5K and carbon monoxide pressures up to 108kPa. It was found that zeolite 5A had the highest adsorption capacity at 298K and ambient pressure (108kPa), whereas MOF-177 was a better adsorbent at 194.5 and 237K. Both the Langmuir and Freundlich isotherm models were used to correlate the adsorption isotherms. Diffusivities of carbon monoxide in these adsorbents were estimated from the adsorption uptake curves by a micropore diffusion model. The average carbon monoxide diffusivities at 298 K and carbon monoxide pressures below 108kPa were 3.42·x 10-11, 1.40·x 10-11, 1.72·x 10-8 and 5.01 x 10-9m2/s for zeolite 5A, 13X, MOF-5 and MOF-177, respectively. The heat of adsorption of carbon monoxide at low coverage on zeolite 5A and 13X was below 70kJ/mol and drops rapidly as the coverage increases, while the heat of adsorption of carbon monoxide in MOF-5 and MOF-177 was in the range of 16 to 22kJ/mol.

Adsorption Equilibria and Kinetics of Carbon Monoxide on Zeolite 5A, 13X, MOF-5, and MOF-177. D.Saha, S.Deng: Journal of Chemical and Engineering Data, 2009, 54[8], 2245-50