In chemical catalysis, analyses of processes involving formation and breaking of bonds play key roles. In this contribution, core-shell structure electrocatalysts for proton exchange membrane fuel cells (PEMFC) are presented. In particular, qualitative and quantitative characteristics of the surface morphology of the electrocatalysts are investigated. Chemical and physical properties are determined through adsorption processes. Physisorption of molecular nitrogen is analysed to calculate the specific surface area S, expressed as m2/g, and to study micro- and meso-porosity of the electrocatalysts. Several mathematical models are applied to identify the more appropriate. 

Processes for water adsorption are designed to understand the hydrophilic and hydrophobic properties of the electrocatalysts. Furthermore, through the study of the real density of the electrocatalysts it is possible to formulate a new parameter, such as the surface area per volume Σ, expressed as m2/cc, which is crucial for the design of an efficient membrane electrode assembly (MEA). From the results of the morphological (surface area and porosity) and composition investigations (using elementary analysis CHNS, XPS and EDX) it is possible to establish correlations with ex situ electrocatalytic performances (using RRDE). [1-4]

References
[1] E. Negro, A. Nale, K. Vezzù, G. Pagot, S. Polizzi, R. Bertoncello et al. Electrochimica Acta, 2018, 280, 149-162.
[2] V. Di Noto, E. Negro, A. Nale, P. Kulesza, I. A. Rutkowska, K. Vezzù et al. Electrocatalysis, 2020, 11(2), 143-159.
[3] M. Mazzucato, G. Daniel, A. Mehmood et al. Applied Catalysis B. Environmental, 2021, 291, 120068.
[4] E. Negro, K. Vezzù, F. Bertasi, P. Schiavuta, L. Toniolo, S. Polizzi et al. ChemElectroChem, 2014, 1, 1359-1369.