Inkjet Printing of Electrochemical Flow-through Membranes Using Chitosan-Reduced Precious Metal Inks for Applications in Electrocatalysis

Electrochemical flow-through membranes (EFMs) are tailored for electrochemical flow systems and show potential for applications in energy conversion and environmental remediation, owing to their efficiency and sustainability. Inkjet printing represents a promising and potentially scalable approach for the fabrication of EFMs. However, conventional metal nanoparticle inks often fail to form reliable coatings on porous ceramic substrates. In this study, we introduce an approach utilizing chitosan-assisted reduction of Pd and Pt salt precursors to create stable, printable nanoparticle inks. Chitosan facilitates in situ nanoparticle formation (<60 nm) with favorable rheology and strong substrate adhesion. Post thermal treatment at 650 °C in an Ar atmosphere, the printed films form a triphasic structure comprising metal nanoparticles, amorphous carbon, and ceramic support. The resulting EFMs exhibit high electrical conductivity, excellent water permeability (∼20 LHM at 0.30 bar), and robust electrochemical performance and stability. This study demonstrates a promising and scalable fabrication strategy for EFMs, with potential applicability in electrocatalysis and membrane-based electrochemical processes.