Seeding strategies for the deposition of high density network of nanoporous Au cluster catalyst on glassy carbon electrodes

Recent developments demonstrated the feasibility of functionalized nanoporous Au (NPG) for application in catalysis. This work employed a variety of seeding strategies aimed at facilitating the synthesis of ultra-high density or nearly continuous cluster network on glassy carbon (GC) surfaces of quality and structure achievable on metal substrates only. The NPG synthetic process involving electrodeposition of AuxAg(1-x) alloy and its subsequent de-alloying was performed on seeds generated by electrodeposition (Cu, Ag) and electroless (Pd, Au) approaches. The outcome of the densification process was assessed by electrochemical characterization and scanning electron microscopy. While some improvement was observed on Cu and Ag seeds, significantly higher nucleation density was obtained on Au-seeded GC surfaces where the deposit featured most typical de-alloying behavior leading to highest surface area evolution. The best overall quality of NPG film manifested by high density networks of overlapping, uniform, and very small clusters nearing structural continuity was achieved on Pd-seeded GC samples.