Dynamic transformation of cubic copper catalysts during CO2 electroreduction and its impact on catalytic selectivity

Philipp Grosse,See Wee Chee,Clara Rettenmaier,Beatriz Roldan Cuenya,Aram Yoon,Antonia Herzog

doi:10.1038/s41467-021-26743-5

Abstract

To rationally design effective and stable catalysts for energy conversion applications, we need to understand how they transform under reaction conditions and reveal their underlying structure-property relationships. This is especially important for catalysts used in the electroreduction of carbon dioxide where product selectivity is sensitive to catalyst structure. Here, we present real-time electrochemical liquid cell transmission electron microscopy studies showing the restructuring of copper(I) oxide cubes during reaction. Fragmentation of the solid cubes, re-deposition of new nanoparticles, catalyst detachment and catalyst aggregation are observed as a function of the applied potential and time. Using cubes with different initial sizes and loading, we further correlate this dynamic morphology with the catalytic selectivity through time-resolved scanning electron microscopy measurements and product analysis. These comparative studies reveal the impact of nanoparticle re-deposition and detachment on the catalyst reactivity, and how the increased surface metal loading created by re-deposited nanoparticles can lead to enhanced C2+ selectivity and stability.

Highlights

To rationally design effective and stable catalysts for energy conversion applications, we need to understand how they transform under reaction conditions and reveal their underlying structure-property relationships
We track the dynamic evolution of electrochemically synthesized Cu2O cubes in real-time under CO2RR conditions with EC-transmission electron microscopy (TEM) and correlate the changes with the catalyst behavior obtained from benchtop electrochemical measurements
We have presented a realistic picture of how Cu2O catalysts dynamically re-structure under CO2RR reaction conditions using both in situ and ex situ electron microscopy, providing insight into the kinetics of different dynamical processes such as re-deposition, agglomeration, detachment, dissolution, and fragmentation[16]

Summary

Introduction

To rationally design effective and stable catalysts for energy conversion applications, we need to understand how they transform under reaction conditions and reveal their underlying structure-property relationships. Using cubes with different initial sizes and loading, we further correlate this dynamic morphology with the catalytic selectivity through time-resolved scanning electron microscopy measurements and product analysis. These comparative studies reveal the impact of nanoparticle re-deposition and detachment on the catalyst reactivity, and how the increased surface metal loading created by re-deposited nanoparticles can lead to enhanced C2+ selectivity and stability. Our results indicate that a dense working catalyst network made up of stable nanoporous cubes and re-deposited NPs can sustain high CO2RR selectivity towards C2+ products

Methods

Results

Conclusion