Catalysts, solid, isotopic exchange with

Carboxylic acids can be prepared by exchange with 0 -enriched water, as is seen from Table V. HCl is used as catalyst if the acid is solid, and perchloric acid is best used if the acid can be distilled off easily in vacuo. Isotope exchange is the easiest method of preparing amino acids (Meats and Sobotka, 1939 Rittenberg and Ponticorvo, 1956). Aldehydes and ketones can also be prepared by this method, but the facile isotopic exchange with water, which is both acid and base catalyzed... 

That products of intermediate oxidation level can be detected in the photocatalytic reactions of hydrocarbons and fossil fuels is also consistent with a surface bound radical intermediate . Photocatalytic isotope exchange between cyclopentane and deuterium on bifunctional platinum/titanium dioxide catalysts indicates the importance of weakly adsorbed pentane at oxide sites. The platinum serves to attract free electrons, decreasing the efficiency of electron-hole recombination, and to regenerate the surface oxide after exchange. Much better control of the exchange is afforded with photoelectrochemical than thermal catalysis > ) As before, hydrocarbon oxidations can also be conducted at the gas-solid interface... 

The study of the catalysis of isotopic exchange in molecular oxygen has begun rather lately and covers a limited number of catalysts and a rather narrow region of variation of conditions for carrying out reactions. Nevertheless, the results obtained enable us to hope that this type of reaction will be a useful method for the study of the mechanism of reactions of oxidation, and especially for the elucidation of nature of intermediate forms of oxygen interaction with solid catalysts. 

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