The research objective of the project SPECTROSCOPE is the in operando X-ray Absorption Spectroscopy (XAS) study of novel non-precious metal electrocatalysts in low temperature polymer-electrolyte-membrane fuel cells (PEMFC) and electrolyzers (PEMEL), also involving the development of a synchrotron platform for such cells. The investigated materials will be metal-nitrogen-carbon and metal-chalcogenide catalysts for oxygen reduction and hydrogen evolution, respectively. A combined experimental-theoretical approach by employing operando X-ray absorption synchrotron techniques (XANES, EXAFS) with advanced ab initio modelling tools will provide unprecedented structural and electronic information on the nature, number and modifications of active sites during oxygen reduction and hydrogen evolution under operation in PEMFC and PEMEL, respectively. Novel structural and mechanistic insights governing the activity and, even more critical, the degradation of such materials will be acquired for the first time under operating conditions and in the environment of PEM-based cells, characterized with a polymer electrolyte, moving the field beyond liquid-electrolyte XAS studies performed hitherto. This will allow us establishing novel understanding and guidelines for durable PEM cells catalyzed by non-precious metal electrocatalysts in the near future.