Surface, dehydration electrical conductivity

It should be observed that in several cases the relation between the electrical conductivity and the activity may break down. This will occur in those intervals of variation of ,+, in which the reaction rate is independent of e,+, e.g., for the reaction of dehydrogenation of alcohols in the region of sufficiently high values, and for dehydration in the region of sufficiently low values of e,+ (Sec. V,B and Fig. 19). It may also occur in the case of a semiconductor with a quasi-isolated surface, when e,+ is independent of e,+ (Sec. VI,B) if the dimensions of the crystal are not too small (Sec. VI,C). 

Soc. Japan 47 1139-1142 Kaneko, K. Inouye, K. (1976) Electrical conductivity changes in a-FeOOH and K-FeOOH upon surface dehydration. Bull. Chem. Soc. Japan 49 3689-3690... 

In conclusion, partially dehydroxylated oxide surfaces exhibit a large inventory of surface OH groups and water molecules together with Lewis acidic and Lewis basic sites with coordinative unsaturation (structures II and III of Scheme 1). The hydroxyl population is the souree of protons that cause enhanced surface electrical conductivity and catalytic activity. It is significant that the increase in the conductivity value is paralleled by increases in either the amount of weakly bound protons or their mobility [48]. Almost all metal oxides are active in catalytic isomerization of alkenes, which is one of the least demanding reactions in terms of the requirements for the acid strength of active sites [34]. Studies on several oxide systems show that the activity is lost after extensive dehydration and is partially restored by... 

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