Nano-electrochemistry at bimetallic electrodes: Influence of dimensionality and structure

The electronic and chemical as well as electrochemical properties of solid surfaces change increasingly when approaching the regime of nanoscaled systems. Furthermore, they are considerably affected also by the dimensionality of the respective nanostructures. Finally, for bimetallic solids/surfaces, the composition of the surface regions and the lateral/vertical distribution of the components play a decisive role. Thus, by varying the two parameters ‘(surface) composition’ and ‘dimensionality’ it is possible to finely tune the chemical/ electrochemical properties of bimetallic nanostructures.

The present combined experimental/theoretical project aims at a detailed, atomic/molecular scale understanding of the electrochemical and -catalytic properties of bimetallic nanostructures of different dimensionality and structure. This problem shall be approached using two complementary bimetallic systems, PtRu (Pt + smaller, active platinum group metal) and PtAu (Pt + larger, inert coinage metal), where we will prepare and investigate in a parallel approach structures of different dimensionality. This includes zero-dimensional nanoparticles, supported on graphene films or on self-assembled organic monolayers (SAMs), as well as one- and two-dimensional surface structures. Both bimetallic systems are highly relevant as electrocatalysts (PtRu, in fuel cells) or discussed as highly interesting material because of its interesting electrocatalytical properties (PtAu). We will employ a variety of microscopic, in-situ as well as ex situ spectroscopic and electrochemical methods as well as theoretical methods based on density functional theory. Further development of these methods for the present applications is part of the project. In a final step we aim at developing concepts to use such kind of structuring procedures for optimizing the electrochemical/-catalytic properties of bimetallic electrodes for applications in the area of energy relevant electrochemistry, specifically for water electrolysis and fuel cell electrocatalysis.

In total, this project aims at the understanding and solving of fundamental problems of nano-electrochemistry, as a basis for a range of highly relevant applications in renewable energy concepts.