Adsorption and desorption of CO on clean and CO pre-covered Mo(1 1 0) have been studied by temperature programmed desorption (TPD), low energy electron diffraction, X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. It was found that adsorption and subsequent desorption of CO from Mo(1 1 0) and CO pre-covered Mo(1 1 0) show large differences in the TPD spectra in the low temperature region from 150 to 400K. In the case of the pre-covered sample a dramatically increased width to lower temperatures was observed. The increased width at higher CO coverage is argued to result from a distribution of adsorption sites and increased lateral interactions between adsorbed CO molecules. (C) 2015 Elsevier B.V. All rights reserved.