Hydrogen peroxide has many industrial uses — for example as a bleaching agent in paper and textiles — as well as widespread use as a disinfectant. It is usually synthesized on a large scale through the anthraquinones oxidation process, although a point-of-use process would be advantageous, circumventing problems with the storage and transport of concentrated H2O2. A direct synthesis — simply using H2 and O2 in the presence of a catalyst — has received recent attention but known catalysts are problematic as they also promote H2O2 hydrogenation and decomposition.

Now, Graham Hutchings of Cardiff University and colleagues from the USA have developed1 a catalyst that is able to switch off the decomposition of H2O2, improving the productivity of the direct process and providing a simple route that could be used in small-scale H2O2 production. Gold–palladium alloy nanoparticles fixed to a carbon support were used as the catalyst, and the key step in improving their activity was found to be an acid pretreatment of the carbon support.

Using electron microscopy, the researchers observed that the acid pretreatment results in a reduction in the size of the alloy nanoparticles that form on the support. These smaller particles are able to decorate and inhibit sites responsible for H2O2 decomposition without affecting its synthesis.