The direct synthesis of hydrogen peroxide from hydrogen and oxygen offers a cleaner more atom efficient alternative to the current commercial production process for this important commodity chemical. We have shown that the incorporation of Au in to Pd catalysts to form supported nanoalloys gives catalysts that synthesise H2O2 with high selectivities in the absence of acid and halide stabilisers. Particularly high activity is observed when an activated carbon is used as a support. However, the activity is very dependent on the choice of carbon. The aim of this proposal is to use to TOSCA to compare two carbons that lead to very different catalyst activities with a view to understanding what are the properties of the support requred for good activity.