S.A. Razavi et al. 3D-printed Ni/γ-Al2O3 catalysts for CO2 methanation: Effect of Ni loading and sintering temperature. Chemical Engineering Journal

S.A. Razavi, G. Fargas, I. Serrano, M.A. Laguna-Bercero, T. Vilella, L. Llanes, D. Rodríguez, M.P. Ginebra, J. Llorca, M. Morales. 3D-printed Ni/γ-Al2O3 catalysts for CO2 methanation: Effect of Ni loading and sintering temperature. Chemical Engineering Journal 523 (2025) 168665. OPEN ACCESS.

doi: doi.org/10.1016/j.cej.2025.168665

Abstract

Additive manufacturing (AM) technologies are revolutionizing the production of ceramic components, particularly in fields like catalysis, where complex shapes offer remarkable advantages in performance. AM also minimizes material waste while reducing the number of fabrication steps. This work is focused on the fabrication of Ni/γ-Al2O3 monoliths for CO2 methanation in one step by using Direct-Ink Writing (DIW) of Ni-enriched hydrogel-based γ-Al2O3 inks, and the debinding and sintering in a single thermal treatment. For this purpose, the influence of Ni precursor amount (2.5–5.0 wt% Ni) on the rheological properties of inks and the catalytic activity is investigated. Monoliths with woodpile architecture and 50 % infill are sintered at 450 °C and 600 °C to determine the effect of the sintering temperature on the Ni distribution in the catalyst. Results evidence successful incorporation of the metallic active phase into the monolithic structures. Both the Ni amount and sintering temperature are key factors to enhance the CO2 methanation performance. The 5.0 wt% Ni monolith sintered at 450 °C presents both the highest CO2 conversion and methane selectivity at 350–500 °C, due to better reduction degree, dispersion, and smaller size of Ni nanoparticles at the maximum metal loading. These remarkable results demonstrate the potential of DIW for the fabrication of fully 3D-printed monolithic catalysts with well-dispersed metal particles, all while minimizing production steps.