Probing CO 2 Conversion Chemistry on Nanostructured Surfaces with Operando Vibrational Spectroscopy.

With the rising emphasis on renewable energy research, the field of electrocatalytic CO2 conversion to fuels has grown tremendously in recent years. Advances in nanomaterial synthesis and characterization have enabled researchers to screen effects of elemental composition, size, and surface chemistry on catalyst performance. However, direct links from structure and active state to catalytic function are difficult to establish. To this end, operando spectroscopic techniques, those conducted simultaneously as catalysts operate, can provide key complementary information by investigating electrocatalysis under turnover conditions. In particular, Raman and infrared spectroscopy have the potential to reveal the identity of surface-bound intermediates, catalyst active state, and possible reaction sites to supplement the insights extracted from conventional electrochemistry. Such research aims to work in tandem synthetic and catalytic efforts to guide the development of next-generation CO2 electrocatalytic systems through rational design. In this Mini Review, we examine the latest developments in the operando probing of electrochemical CO2 reduction on nanostructured electrocatalysts and detail how this research accelerates the advancement of this field.