Universal Scaling and Trends in Activity

The difference, AG2 = (AG° - AG110 ), is therefore a unique descriptor for the OER activity, and the theoretical overpotential at standard conditions is 

Please note that this only relates to the catalysis materials may not be suited for electrodes for many reasons, such as surface area, stability, and conductivity. In reality, all of these issues are of course important. 

When comparing to experiments, it has to be taken into consideration that no measured quantity directly corresponds to r OER as it is calculated however, the assumptions were that differences in measured catalytic activity at least should scale with the size of the potential-determining step and that barriers should not significantly change that. In OER experiments on rutile and perovskites, the potential at a given current density is seen to scale very nicely with the calculated r OER [17]. 

It is possible to capture the trends in OER activities observed in experiments with the simple analysis discussed previously. The hypothesis is that the main difference in activity between two catalysts is related to the difference in the potential needed to drive the most difficult reaction step. The main assumption is that barriers along the reaction scale with the reaction free energies see also the original literature [13, 17,21], 

Whitesides GM, Crabtree GW. Don t forget long-term fundamental research in energy Science. Science. 2007 315 796. 

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