Nanoparticle-Promoted and Nanoparticle-Suppressed Behavior of Pd/C Catalytic Systems Revealed by a Digital Assistant for Electron Microscopy Data Quantification

Abstract

Various transition metal particles on assorted carbon supports form the family of metal-on-carbon (M/C) catalysts, which are of particular importance for the chemical industry and laboratory research. Obtaining comprehensive information about the structure of these materials at different scales is essential for developing new synthesis methods, identifying potential applications, and predicting M/C properties. Although electron microscopy is a convenient method for the direct visualization of supported metal particles, the locality and specificity of such analysis can limit the establishment of relationships between the observed nanostructure and catalytic properties. This paper introduces an approach for converting local microscopy data into quantitative structural metrics for catalytic studies. A series of palladium-on-graphite (Pd/C) materials was synthesized and characterized using a digital assistant for rapid image processing, enabling a multiparametric description of the nanoscale phase through metal surface density and particle distribution parameters. Applied to Mizoroki–Heck and transfer hydrogenation reactions, these descriptors revealed nanoparticle-promoted and nanoparticle-suppressed catalytic behavior, highlighting an alternative perspective on evaluating the role of nanoscale phases in supported metal catalysts. Rather than replacing traditional structural and mechanistic approaches, this method was shown to complement them, expanding electron microscopy applications in catalytic system design.