Fabrication of 3D-Printed Reactors for Heterogeneous Photocatalysis

Abstract

As part of the development of 3D-printed photocatalytic reactors for greenhouse gas treatment, two reactor configurations were fabricated: a planar geometry and a shell-and-tube design, both intended for gas-phase CO₂ photoreduction over mesoporous TiO₂ photocatalysts modified with copper oxides (Cu_xO). To ensure the airtightness of the printed parts, two sealing strategies were developed: the first based on applying a solvent that partially dissolves the outer layers of the printed material, promoting their fusion and sealing upon evaporation; the second through a modification of the printing method (brick-layering), which reduces the interlayer porosity typical of fused deposition additive manufacturing. Both strategies were evaluated through permeability testing. In parallel, an in-house NO_x analyzer was commissioned to quantify reaction by-products in the photocatalytic assays, and a collaboration was established with Centro Atómico Bariloche for quantifying CO₂ conversion via FTIR and gas chromatography (GC-TCD/FID). A series of TiO₂-Cu_xO photocatalysts have already been synthesized and characterized, ready for evaluation in the developed reactors. These advances represent a key step toward the comprehensive experimental validation of the proposed photocatalytic system.