Contrasting reaction pathways in methanol oxidation on Cu(110) studied by STM

Scanning tunnelling microscopy (STM) has been employed in studying the adsorption and reaction of methanol and oxygen on Cu(110) during co-dosing. We have observed the production of formate c and structures at 300 K during co-dosing. This strongly contrasts with the established case of sequential dosing, since oxygen precovered Cu(110) surfaces are seen to have negligible activity toward formate production when subsequently dosed with methanol. During co-dosing formate and methoxy groups are seen as the main reaction products while oxygen reconstructed areas poison the formate production channel. Competition for isolated oxygen adatoms between the O islands and methoxy groups is seen as determining the rate of formate production. Methanol rich gas mixtures have the highest efficiency for formate production whereas an oxygen rich gas phase composition does not produce formate due to preferential growth of O islands.