An overview of solid-state electron paramagnetic resonance spectroscopy for artificial fuel reactions

The use of spectroscopy to characterize electrocatalytic processes is vital to the understanding and continuing the development of new catalysts for clean energy transformations. Electron paramagnetic resonance spectroscopy (EPR), which allows for the study of unpaired electron spins, shows great fundamental promise for the study of electrocatalysts, but was previously hindered by design limitations. Recently, several groups have demonstrated that these limitations can be overcome, providing valuable understandings of electrocatalyst function that other techniques are less suitable for. In this review, we summarize these findings across a range of experimental approaches and systems and describe the importance of EPR to each of these studies. By providing outlines for how these studies were able to overcome experimental design challenges, we hope to provide insight into potentially interested users.