A study addresses the shape evolution of carbon supported Pt nanoparticles from cubooctaedron to concave cubic and branched like structures.

Nanoparticles were synthesized by water-in-oil microemulsion method with addition of HCl and Vulcan XC-72R as the particles support.

Addition of the support facilitated the cleaning procedures enabling the application of the catalysts without the electrochemical treatment.

XRD and TEM results revealed that synthesized particles are smaller in size (4–8 nm) compared to some previously reported.

Concave cubic particles with electrochemically detectable {100} preferentially oriented facets show improved catalytic properties.