Abstract
We study the adsorption of thiophene on Al(100), Ir(100), W(100), Mo(100), Cr(100), Ta(100), Nb(100), V(100), and Co(10-10) surfaces using density functional theory specifically the van der Waals inclusive optB88-vdW functional. We present a thorough report detailing the geometric and electronic structure of the adsorbate/substrate systems including adsorption heights, adsorption energies, buckling of the first layer of the substrate, C-S bond distances, modification of the surfaces d-band, change in the surfaces work function, and charge transfer to the thiophene molecule. Altogether, we observe a breaking of a single C-S bond when thiophene adsorbs over Mo(100), and the breaking of up to two C-S bonds when thiophene adsorbs over Cr, Ta, Nb, and V(100). We note a direct correlation between the charge transferred to the thiophene molecule, specifically thiophene's S atom, and thiophene's propensity to break C-S bonds over these surfaces, leading us to frame the desulfurization of thiophene as a process governed by charge transfer.