One of the top priorities of human society is addressing climate change. Clean electrochemical technology is a vital part of the transformation necessary to meet climate goals and net-zero CO₂ emissions by 2050. Electrochemical technology of high interest includes water electrolysis for green hydrogen generation, fuel cells for emission free transportation, and electrochemical CO₂ reduction for achieving net-zero CO₂ emissions. One critical challenge for wide-scale adoption of these electrochemical technologies is the long-term device durability. Comprehensive understanding the degradation phenomenon and underlying mechanism is of critical importance for technology and product development. In this regard, in-operando and in-situ techniques, providing unique and direct insight into the degradation process in these electrochemical devices, play important roles for advancing such understanding and ultimately increasing long-term durability.

Such techniques often rely on combined electrochemical diagnostics with advanced spectroscopy or other imaging capable of temporal and spatial resolution. In-operando techniques are often challenging due to the need for unique electrochemical cell configurations that fulfill the requirements of the technique while at the same time delivering electrochemical behavior similar to a commercial device.

The talk will first discuss a mapping methodology based on synchrotron X-ray micro-diffraction to study the heterogeneous degradation. Information obtained from the method and examples of application to study platinum catalyst degradation in accelerated stress tests will be discussed. The utility of correlating large datasets of in-situ electrochemical diagnostics from a variety of accelerated aging tests with the spatially resolved diffraction mapping will also be presented.