  We have performed dispersion-corrected density-functional transition state
calculations on atomic Au- and Pd- catalysis of water conversion to peroxide.
The Au- ion is found to be an excellent catalyst; however, atomic Pd- has a
higher catalytic effect on the formation of peroxide. The Au^{-}(H2O)2 and
Pd^{-}(H2O)2 anion molecular complexes formation in the transition state is
identified as the fundamental mechanism for breaking the hydrogen bonding
strength during the water catalysis. Our theoretical results provide crucial
insight into the mechanism of the atomic Au- and Pd- catalysis in good
agreement with recent experimental observations.
