ACETIC-ACID DECOMPOSITION ON A POLYCRYSTALLINE PLATINUM SURFACE

The decomposition of CH//3**1**3COOH on a polycrystalline platinum surface has been examined at temperatures between 300 and 900 K during continuous exposure to CH//3**1**3COOH at 7 multiplied by 10** minus **4 Torr. On an initially clean platinum surface **1**3CO, CO, **1**3CO//2, H//2 and adsorbed carbon-12 are the major reaction products. For temperatures above approximately 800 K, the carbon overlayer that is formed is graphitic and saturates at a carbon adatom concentration of (2. 6-3. 5) multiplied by 10**1**5 cm** minus **2. The reaction quantities of **1**3CO and **1**3CO//2 that are produced depend both on the surface temperature and the carbon coverage. Lower temperatures and higher carbon coverages favor the production of **1**3CO. On the graphitized platinum surface, the catalytic dehydration of acetic acid to ketene and water proceeds at steady-state.