Microstructural origin of locally enhanced CO2 electroreduction activity on gold

Understanding how the bulk structure of a material affects catalysis on its surface is critical to the development of actionable catalyst design principles. Bulk defects have been shown to affect electrocatalytic materials that are important for energy conversion systems, but the structural origins of these effects have not been fully elucidated. Here we use a combination of high-resolution scanning electrochemical cell microscopy and electron backscatter diffraction to visualize the potential-dependent electrocatalytic carbon dioxide (CO2) electroreduction and hydrogen (H-2) evolution activity on Au electrodes and probe the effects of bulk defects. Comparing colocated activity maps and videos to the underlying microstructure and lattice deformation supports a model in which CO2 electroreduction is selectively enhanced by surface-terminating dislocations, which can accumulate at grain boundaries and slip bands. Our results suggest that the deliberate introduction of dislocations into materials is a promising strategy for improving catalytic properties.

Automated summary

The study demonstrates that understanding the relationship between surface catalytic activity and bulk defects, such as dislocations, could lead to improvements in catalytic properties, particularly in CO2 electroreduction. Intentionally introducing dislocations into materials appears to be a promising strategy for enhancing catalytic activity.