Abstract
The effect of 
on the oxidation of hydrogen atoms chemisorbed on a Pt electrode has been examined with potentiostatic and transient galvanostatic techniques. The results indicate that 
is not reduced, but that 
oxidation is inhibited by 
, or possibly 
. Under these conditions the inhibited or blocked Had is stable at potentials negative to 0.3v (vs. NHE). Dissociation of formic acid to 
and 
may inhibit the further oxidation of 
by a similar 
blocking mechanism.