Research Overview

Electrocatalyst Restructuring During Operation

Electrocatalysts are an important component of our chemical infrastructure, allowing electrons to serve as reagents in the synthesis of important chemicals with applications in renewable energy storage, water sanitation, pharmaceuticals, and polymers. While in principle a catalyst is reversibly replenished after each turn-over, it is well-known that many electrocatalysts undergo irreversible structural changes under electrochemical operation. These changes can be beneficial and lead to the formation of a metastable state that has improved catalytic activity, or they could be deleterious and lead to the gradual degradation of the electrocatalyst. The Moreno-Hernandez Lab observes structural changes of electrocatalysts during operation directly with liquid cell transmission electron microscopy, which provides structural information necessary to further improve predictions of electrochemical activity and inform strategies for the synthesis of improved electrocatalysts.

 

Material Deposition at Nanoscale Heterogeneous Interfaces

Deposition of materials has enabled countless technologies for over 200 years, enabling applications such as anti-corrosion coatings and the deposition of electrical contacts for most electronics. In recent years, advances in deposition have enhanced control of material growth at the nanoscale, enabling the synthesis of complex structures consisting of many elements via fine control of the deposition reactions. Understanding the dynamics that occur at the nanoscale is crucial to enable future technologies and synthesize more complex materials. A challenge with understanding these dynamics is that most techniques are not able to probe the deposition dynamics in situ, requiring post-deposition studies to understand the growth dynamics at the nanoscale. The Moreno-Hernandez Lab uses liquid cell transmission electron microscopy to directly observe the formation of nanomaterials during the growth process, with a particular interest in growth occurring at the heterogeneous interfaces that form between two dissimilar materials.

 

Ion-Intercalation Dynamics of Nanoscale Battery Materials

Electrochemical energy storage has become an integral part of our society’s energy infrastructure, enabling technologies such as wireless personal computing devices. There have been many advances in the last 50 years in the stability, energy density, and efficiency of batteries. However, further advances in performance are necessary to meet the increasing demand for high power applications that include transportation and energy storage of intermittent renewable energy sources. A key aspect of developing materials to meet this demand is an accurate understanding of the structural dynamics of battery components during ion intercalation or removal. The Moreno-Hernandez Lab studies the ion-intercalation dynamics of battery materials using liquid cell transmission electron microscopy, a technique that enables direct spatiotemporal imaging of the complex dynamics that occur at solid electrolyte interfaces.