The mechanism of methanol dehydrogenation to methyl formate (MF) was s
tudied over a copper-zirconium alloy catalyst sample prepared from an
amorphous precursor. As a result of a special activation procedure, a
catalyst of stable activity was obtained suitable for mechanistic stud
ies. A mixture of CH3OD and CD3OD was used in various ratios to study
the isotope distribution of unreacted methanol and product MF. The D/H
ratio in the formyl group is similar to that of the feed mixture. Sim
ilarly, considerable D/H randomization was found in the methyl group o
f methyl formate. These results suggest that fast dehydrogenation-hydr
ogenation equilibrium steps occur prior to the formation/desorption of
methyl formate. The mechanism of the reaction can be rationalized ass
uming an intermediate which we call equilibrated surface formyl/format
e group.