Simple and high-yield preparation of carbon-black-supported ∼1 nm platinum nanoclusters and their oxygen reduction reactivity

The improvement of oxygen reduction reaction (ORR) catalysts is essential before polymer electrolyte fuel cells can be used widely. To this end, we established a simple method for the size-selective synthesis of a series of ligand-protected platinum nanoclusters with similar to 1 nm particle size (Pt-n NCs; n = similar to 35, similar to 51, and similar to 66) and narrow size distribution (+/-similar to 4 Pt atoms) under atmospheric conditions. Using this method, each ligand-protected similar to 1 nm Pt NC was obtained in a relatively high yield (nearly 80% for Pt-similar to 66). We succeeded in adsorbing each ligand-protected similar to 1 nm Pt NC on carbon black (CB) and then removing most of the ligands from the surface of the Pt NCs via calcination while maintaining the original size. The obtained Pt-similar to 35/CB, Pt-similar to 51/CB, and Pt-similar to 66/CB exhibited ORR mass activities that were 1.6, 2.1, and 1.6 times higher, respectively, than that of commercial CB supported-Pt nanoparticles, and also display high durability.

Automated summary

A simple method was established for the size-selective synthesis of ligand-protected platinum nanoclusters with similar particle size, achieving high yield. The ligand-protected Pt nanoclusters exhibited higher ORR mass activities on carbon black compared to commercial nanoparticles, showing improved durability.