The Mechanism and Electrocatalysis of Methanol to Carbon Dioxide

One of the functions of methanol is as a fuel for fuel cells. The general concept is that the best fuel for that purpose is hydrogen, and there is no doubt that the high ja ( 10 3 A cm 2) for hydrogen 

methanol could be a practical fuel while hydrogen, with its need for a high-pressure container, would not be. On the other hand, compared with hydrogen, methanol has certain defects, which might be overcome if we knew its mechanics of oxidation and could thus think about its 

In contemplating such studies, an important characteristic has to be revealed. When an electrochemical reaction is carried out quickly (seconds) its mechanism may differ from that which operates when it is to function in hours or even months and years. There are two general methods of study of the kinetics of electrode reactions. In the first, the potential sweep approach, the current density is recorded while the potential is moved at a steady rate toward the more positive (or anodic) side. Thus, the results do not necessarily correspond to those which would be felt if the fuel cell was supposed to be the power source for long periods, driving cars, for example. 

Another method (potentiostatic) involves keeping the potential constant and examining the current over seconds, minutes, etc. Now, one gets to know the behavior of the cell in a longer, more practical time zone in which it is to function in practice. The current-time relation is measured at a series of potentials corresponding to those of practice and from these results one can construct the log j, -T) relation, which may help with mechanism determination. 

This latter method can be called potentiostatic, and its results in general correspond more to the steady-state condition of practical use than do the potential sweep treatments that involve potential changes all the time measurements are being made. 

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