Thermodynamic and kinetic investigation for peroxide hydrogen reduction reaction on nanoporous electrocatalysts

Owing to the unique three-dimensional bi-continuous (pore and ligament) structure of nanoporous metals, active sites and electron conduction are both promoted for electrocatalytic reactions. However, the narrowing pore sizes for increasing surface areas provide more active sites but hindered mass diffusion. Therefore, there are optimal values for the ligament and pore size of nanoporous metal electrocatalysts. As an outstanding electrocatalyst towards hydrogen peroxide reduction reaction (HPRR), the structure features of nanoporous gold (NPG) were investigated in detail by using electrochemical techniques, e.g., rotating disk electrode (RDE) in this paper. The experimental results demonstrated that residual silver in NPG did not afford a positive effect for HPRR although exhibiting good catalytic activity alone. Furthermore, by comparing the thermodynamic and kinetic properties of NPG samples with various ligament/pore sizes, NPG electrocatalyst with pore size of ~ 30 nm exhibited an optimal catalytic activity and stability for HPRR.