Pechini-based reactive-binder ceramic suspension for direct ink writing of phase-pure structured SnO2 catalyst supports

Tin oxide (SnO2) is a chemically stable, redox-active metal oxide widely employed as a catalyst support in heterogeneous reactions, gas sensing, and energy-related applications. Here, we present a novel approach for the additive manufacturing of structured SnO2 catalyst supports via direct ink writing (DIW), utilising a Pechini-derived reactive binder. The ink formulation combines commercial SnO2 powder with a polymerisable complex of tin, citric acid, and ethylene glycol, which functions both as a rheological modifier and as a metal oxide precursor. This dual role eliminates the need for inert thickeners or non-native oxide binders. The resulting paste exhibits suitable viscoelastic properties for extrusion-based shaping and, upon calcination, the binder decomposes and converts to SnO2, complementing the original solid loading. The sintered pieces retain their geometric integrity, rendering them ideal for catalytic applications requiring high thermal and chemical stability. This reactive-binder strategy offers a straightforward, scalable, and compositionally clean route to structured metal oxide components, with potential applicability to other single or mixed oxide systems.