Direct conversion of methanol to formaldehyde in the absence of oxygen on Cu(210)

Abstract

In the previous literature, people have prepared supported copper catalysts which were modestly active for the direct conversion of methanol to formaldehyde in the absence of oxygen. However, single crystal catalysts have shown much less activity. In this paper, the direct conversion of methanol to formaldehyde was attempted using a very basic copper surface, Cu(210). TPD measurements show that when one adsorbs methanol onto a clean, 100 K, Cu(210) sample, about half of the methanol desorbs intact and about half of the methanol reacts to form formaldehyde and hydrogen: CH 3OH → H 2CO + H 2. The formaldehyde desorbs in a peak centered at 390 K. Some of the hydrogen desorbs in a broad peak between 150 and 350 K, while the remainder desorbs in a peak centered at 390 K. These results show that the Cu(210) surface is special in that it is the only face of copper examined so far that is able to convert a significant amount of methanol to formaldehyde in the absence of oxygen.