Scale‐Up Process of Core@Shell Monolayer Catalyst without Active Potential Control through Electroless Underpotential Deposition Galvanic Replacement

Abstract

Core@shell monolayer catalysts have dual advantages in electrocatalysis, cost of the catalyst is minimized by depositing expensive metal as a monolayer shell and the catalytic activity can be enhanced by selecting an appropriate core metal. In this communication, a novel chemically assisted underpotential deposition process to fabricate core@shell monolayer nanoparticles in bulk scale has been introduced. Ag(shell)@Pd(core)/C nanoparticles have been prepared by this electroless underpotential deposition method. The thickness of the Ag shell has been calculated as one atomic layer from XPS analysis. Core‐shell structure of nanoparticles has been confirmed by STEM characterization. Further, Pt(shell)@Pd(core)/C nanoparticles have been engineered from Ag@Pd/C nanoparticles by Galvanic replacement of Ag by Pt. This Pt@Pd/C electrocatalyst has been tested for formic acid oxidation.

Construction of Lattice Strain in Bimetallic Nanostructures and Its Effectiveness in Electrochemical Applications

“…Sarkar and co-workers developed a chemically assisted electroless UPD method to fabricate Pd@Ag ML core-shell NCs by depositing Ag on Pd NCs/C. The ML Ag was further galvanically replaced by Pt, [65] and Pd@Pt NCs/C were successfully achieved (Figure 6a). It should be noticeable that the reported Pd@Ag core-shell NCs only consist of half a ML of Pt on Pd NCs/C based on the reaction: 2 Ag + Pt 2 + → 2 Ag + + Pt.…”