Methyl formate formation from methanol oxidation using supported gold-palladium nanoparticles

Recent advances in the oxidation of alcohols to methyl esters using metal nanoparticles have paved the way for more environmentally benign processes, operating at lower reaction temperatures with high product selectivity. Here, we demonstrate the use of bimetallic 1 wt % Au-Pd/TiO2 catalysts that achieve high activity for the oxidation of methanol to methyl formate at low temperature. The application of a water extraction treatment to retain size-stabilized Au-Pd nanoparticles, in contrast to a more standard thermal treatment, provides the most active catalyst for this reaction. Using in situ DRIFTS, we demonstrate that in situ activation during methanol oxidation enhances the catalytic activity at low temperature and that this is a long-lived effect. Surface adsorbates, particularly formate species, build up on the catalyst surface during the reaction and are proven vital to enhancing the catalytic effect. (Chemical Equation Presented)