Exploring thiophene desulfurization: The adsorption of thiophene on transition metal surfaces

•Thiophene breaks one C–S bond over Mo(100).•Thiophene breaks one or two C–S bonds over W(100) and Cr(100).•Thiophene breaks two C–S bonds over V(100), Ta(100), and Nb(100).•The breaking of C–S is mediated by charge transfer to thiophene's S atom. 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 surface's d-band, change in the surface's 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. [Display omitted]