A recent study of temperature programmed desorption (TPD) measurements of small n-alkanes (CNH2N+2) from C(0001) deposited on Pt(111) shows a linear relationship of the desorption energy with increasing n-alkane chain length. We here present a van der Waals density functional study of the desorption barrier energy of the ten smallest n-alkanes (N = 1 to 10) from graphene. We find linear scaling with N, including a nonzero intercept with the energy axis, i.e., an offset at the extrapolation to N = 0. This calculated offset is quantitatively similar to the results of the TPD measurements. From further calculations of the polyethylene polymer we offer a suggestion for the origin of the offset.
@article{arxiv.1205.1295,
title = {Desorption of n-alkanes from graphene: a van der Waals density functional study},
author = {Elisa Londero and Emma K. Karlson and Marcus Landahl and Dimitri Ostrovskii and Jonatan D. Rydberg and Elsebeth Schröder},
journal= {arXiv preprint arXiv:1205.1295},
year = {2015}
}