Thermal desorption spectroscopy (TDS) allows for distinguishing among internal, external, and groove adsorption sites on carbon nanotubes (CNTs). Thus, TDS can be applied to study the effect of CNTs' crystal structure on adsorption kinetics. On clean CNTs, the binding energy for methanol increases with increasing CNT diameter, consistent with theoretical predictions. However, kinetics results can be obscured by rather subtle solvent (impurity) effects which are probe molecule specific.
Bibliographical noteFunding Information:
We thank Ya-Ping Sun (Clemson University) for providing the m-CNT powder. Financial support from the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, US Department of Energy is acknowledged by NDSU (DE-FG02-08ER15987).