DIRECT SYNTHESIS OF FORMATE FROM METHANOL OXIDATION ON THE CUPD[85-15](110)P(2 X-1) SURFACE - INDUCTION OF A NEW REACTION PATHWAY VIA A LIGAND EFFECT

Thermal molecular beam studies of the oxidative dehydrogenation of methanol over the 1/4 ML and 1/2 ML oxygen predosed CuPd[85 : 15]{110}p(2 x 1) surfaces has been performed. Post reaction thermal desorption spectroscopy (TDS) clearly shows that during these experiments observable levels of formate are produced. This is in contrast to the results of similar experiments performed over oxidised Cu{110} surfaces which showed little formate production. It is hypothesised that the alloying in the surface region causes this new reaction pathway to appear as a consequence of a modification of the stability of one or more of the reactive intermediates produced in this reaction. It is proposed that these modifications of adsorbate stability are due to a ligand effect arising from the presence of Pd in the second layer of the selvedge.