Platinum Terpyridine Metallopolymer Electrode as Cost-Effective Replacement for Bulk Platinum Catalysts in Oxygen Reduction Reaction and Hydrogen Evolution Reaction

Conducting
polymers consisting of metal-selective coordination
units and a highly conductive backbone, so-called metallopolymers,
are interesting materials exposing single atoms for photo/electrocatalysis
and thus represent a potential low-cost alternative for bulk or nanoparticulate
platinum group metals (PGMs). We synthesized and fully characterized
an electropolymerisable monomer bearing a pendant terpyridine unit
for the selective complexation of PGMs. Electrocatalytic tests of
the resulting metallopolymer, poly-[(tThTerpy)­PtCl]­Cl, revealed activity
both in the oxygen reduction reaction and hydrogen evolution reaction.
Rotating disk experiments showed the direct four-electron reduction
of molecular oxygen to water at low angular velocities of the rotating
electrode. Furthermore, the fabrication of Pt metallopolymers proved
to be simple, nonhazardous and versatile. This proof-of-concept opens
up the possibility for developing future low-cost electro- and photocatalysts
to replace current systems.