S. A. Razavi et al. Direct recycling of 3D-printed Co-YDZ catalysts for ethanol steam reforming. Journal of Environmental Chemical Engineering

S. A. Razavi, G. Fargas, I. Serrano, M. A. Laguna-Bercero, T. Vilella, L. Llanes, D. Rodríguez, M. P. Ginebra, J. Llorca, M. Morales. Direct recycling of 3D printed Co-YDZ catalysts for ethanol steam reforming. Journal of Environmental Chemical Engineering, November 2025, 120246. OPEN ACCESS.

doi: doi.org/10.1016/j.jece.2025.120246

Abstract

Additive manufacturing enhances the catalyst performance via hierarchical design. To address environmental and resource concerns, this work aims to fabricate directly recycled 3D-printed monoliths using Direct-Ink Writing (DIW) from 100% recovered cobalt-zirconia powders. Virgin cobalt-zirconia monoliths were firstly fabricated by DIW of 3.0 to 7.0 wt% Co-enriched hydrogel-based ceramic inks, followed by calcination at 600°C in a single thermal treatment. After testing the catalytic performance of monoliths in ethanol steam reforming, 3D-printed cobalt-zirconia monoliths were fragmented and subjected to subsequent milling and sieving steps to recover composite cobalt-zirconia powders with the appropriate properties for reuse in DIW. The recovered powders, inks and monoliths were microstructurally, rheologically and catalytically characterized, and then compared to catalysts constituted by virgin materials. The rheology properties of inks for the recycled and virgin monoliths presented an appropriate printability. Furthermore, the catalytic performance of recycled monoliths was close to that exhibited by virgin catalysts. This study demonstrates the feasibility of directly recycling fully 3D-printed catalysts, potentially reducing the environmental impact with a circular production model to enhance sustainability in the catalyst industry.