Electrocatalysis is a key part of renewable energy conversion and storage in the future energy system. For more efficient energy distribution and utilization, multiple nanostructures have been investigated toward optimal electrocatalytic activity. However, stability of electrocatalysts is also crucial for both sustainable and reliable operation of energy devices. Nanoscale electrocatalysts suffer various degradation phenomena during electrocatalysis, which leads to critical performance loss.<br/>For this purpose, we will cover three different types of nanomaterials as robust and active electrocatalysts for oxygen reduction reaction (ORR). First, we will show the strategic employment of carbon shells on electrocatalyst surfaces to enhance stability in electrochemical process. Carbon shells can beneficially shield catalyst surfaces from electrochemical degradation and physical agglomeration. Thus carbon shells can effectively preserve initial active site structure during electrocatalysis. Second, the alloy nanomaterials with ordered structures exhibit novel catalytic properties from their unique electronic and geometric structures. In particular, Pt alloys with atomically ordered crystal structures have been found to largely improve both electrocatalytic activity and stability for ORR through increased electronic interaction between Pt and other transition metals. Similarly, we recently demonstrated that well-controlled Co-, Mn- and Fe-based ternary or binary oxide model nanocatalysts have an exceptionally high ORR activity, in addition to the promising electrocatalytic stability. Therefore, it is very important to synthesize well-ordered alloy nanocrystals to obtain the highly durable and active electrocatalysts with respect to their structural and compositional properties. Finally, we will suggest that exposing facet and surface strain on nanocrystals can be critical factors affecting electrocatalytic performance and also stability. By controlling facet and strain effect on catalytic activity, we can achieve high active and stable metal oxide systems for ORR.<br/>In this presentation, we would like to describe the details of the above results, for investigating composition-structure-activity relationships in electrocatalytic processes. Only when we start to comprehend the fundamentals behind electrocatalysis on the structure and interface of metal/metal oxide nanocrystals, they can be further advanced to be sustainable in long-term device operation.

Development of nanoscale metal/metal oxide materials for highly active and durable electrocatalysts

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.