Mesoscopic understanding of supported catalysts with overlapping electric double layers

Introduction

A defossilized global energy ecosystem hinges on efficient conversion between renewable electrical energy and chemical energy stored in molecules. This conversion requires precious catalysts to drive relevant reactions at practical rates. Many catalysts are employed in the form of nanoparticles (NP) dispersed on support materials.

Electric Double Layer (EDL)

All relevant reactions occur in a nanoscale region at the interface between the solid catalyst and an electrolyte solution, i.e., an electric double layer (EDL). Our current knowledge of EDL is essentially limited to planar electrodes with a single EDL, whereas supported NP catalysts (SNPC) exhibit radically different EDL characteristics.

Characteristics of SNPC

SNPC features overlap of individual EDLs around the NPs and the adjacent support material. This knowledge gap, concerning crucial local reaction conditions within the EDL, prevents effectively transferring knowledge obtained at planar electrodes to performance improvements of SNPC.

Project Objectives

MESO-CAT aims at launching the mesoscopic (1~100 nm) science of overlapping EDLs in SNPC and unraveling the influence of overlapping EDLs on the structure-activity relationship of SNPC. MESO-CAT will address three foundational questions in electrocatalysis of SNPC using theoretical methods in an interaction loop with experimentalists:

1. Formation of Overlapping EDLs
   How are the overlapping EDLs formed under realistic conditions? This will be studied using a unique theoretical approach for mesoscale EDLs with both quantum mechanical electrons and classical electrolyte particles treated on equal footing.

2. Influence on Electron Transfer Kinetics
   How do overlapping EDLs influence elementary electron transfer kinetics? This will be unraveled using a model Hamiltonian for proton-coupled electron transfer considering various EDL effects.

3. Impact on Structure-Activity Relationship
   How do overlapping EDLs influence the overall structure-activity relationship? This will lay the groundwork for transformative advancements in electrochemical energy conversion via regulating the mesoscale EDL effects.