Arginine-glycine-aspartate (RGD) peptide-modified graphene as efficient support material for Pt electrocatalyst in proton exchange membrane fuel cells

Official URL: https://dx.doi.org/10.1002/er.7467

Graphene with its two-dimensional structure and unique properties has immense potential in energy-related applications such as proton exchange membrane (PEM) fuel cells. Herein, we employ a well-known biomolecule arginine-glycine-aspartate (RGD) peptide–functionalized graphene-supported Pt nanoparticles as an electrocatalyst for PEM fuel cells for the first time. First, chemically reactive graphene oxide (GO) is used as a precursor to covalently functionalize it with RGD peptide through amide bond formation. The amino moieties of RGD peptide on graphene surface serve as ligands and active sites for the nucleation and controlled growth of Pt nanoparticles through polyol reduction method. The homogeneous distribution of ultra-small (about 3 nm) Pt nanoparticles supported on RGD functionalized graphene boosted the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) electrocatalytic activities by 52% in electrochemical active surface area (ECSA), 112% in mass activity, and 39% in specific activity as compared to unmodified graphene surface. The strong interaction between the metal and the modified support's surface, assisted in evading serious agglomeration and dissolution during 1000 cycles of accelerated degradation tests (ADT), improving the long-term durability of the Pt electrocatalyst by showing about 21% higher ECSA retention than the unmodified support. Fuel cell performance of RGD functionalized graphene-supported Pt nanoparticles also depicted improved power output due to its better Pt utilization and electrocatalytic activity.