Elevated temperature scanning tunneling microscopy study of formic acid adsorption and reaction on oxygen (2x1) covered Cu(110)

The adsorption and reaction of formic acid on a fully oxygen (2 X 1) covered Cu(110) surface maintained at 353 K has been studied by scanning tunneling microscopy (STM). Formic acid adsorption is followed in a sequence of images that show the removal of oxygen (2 X 1) rows preferentially in the <001> direction. The added copper atoms which were associated with the oxygen reconstruction are Liberated and diffuse to create significant areas of the high oxygen coverage O-c(6 X 2) structure. The adsorbed formate produces a (4 x 1) structure, Analysis of the STM images allows limits to be placed upon the surface structure of the final formate (4 X 1) surface revealing a lower local formate density than produced for room temperature adsorption. These two observations lead to an understanding of the significant drop in formic acid uptake which has been reported for a narrow temperature window between 350-420 K on this surface. (C) 1998 American Institute of Physics.