Here (ads) refers to particles adsorbed on the catalyst surface and (adj) to particles of silver, directly adjacent to the oxygen atoms.
The large surface areas of these solids increase the probability that a reactant molecule in solution will come into contact with the catalyst surface and react.
The catalyst can then be dried and calcined to drive off the volatile components within the solution, depositing the metal on the catalyst surface.
He has collaborated with Gabor Somorjai on the use of the technique of Sum Frequency Generation Spectroscopy to study catalyst surfaces.
The intermediate reaction states were: HO, HO, then HO and the final reaction product (water molecule dimers), after which the water molecule desorbs from the catalyst surface.
This has the effect of increasing the concentration of the reactants at the catalyst surface and also weakening of the bonds in the reacting molecules (the activation energy is lowered).
Surface diffusion is a critically important concept in heterogeneous catalysis, as reaction rates are often dictated by the ability of reactants to "find" each other at a catalyst surface.
In heterogeneous catalysis, the reactants diffuse to the catalyst surface and adsorb onto it, via the formation of chemical bonds.
The stoichiometry of the reaction is given by, but this equation gives no indication of what happens on the catalyst surface: for example, carbon dioxide is almost certainly involved as an intermediate at one stage.
Chemists have begun to develop models for these processes and for the formation of other compounds using soluble metal compounds which are more easily studied than catalyst surfaces.