Influence of the OH groups of hydroxylated rutile (110) surface on the Lewis acidity: an investigation of CO adsorption by quantum-mechanical simulations

The adsorption of carbon monoxide on a clean and hydroxylated rutile (110) surface has been investigated using a periodic approach at DFT/B3LYP level. The hydroxylated surface was modelled by considering both terminal and bridging OH groups. The variation of the electrophilicity of the Lewis acid site near these groups was evaluated by taking into account the adsorbate–substrate distance, the magnitude of the interaction energy and the blue-shift of the adsorbed CO stretching frequency. The results obtained suggest that the electrophilicity increases in proximity to OH terminal groups, and decreases near the OH bridging groups.