Ruthenium-impregnated three-dimensional printed composites for catalytic applications

Abstract This study aimed to perform preliminary research on the properties of three-dimensional (3D) printed lattices, as potential cost-effective catalysts for CO 2 methanation, a key process in sustainable energy systems. SiO 2 –Ni-based catalysts were fabricated employing direct ink writing (DIW) technology, and structures were subsequently crushed and modified with Ru via a conventional impregnation method. Elemental analysis revealed a higher Ru concentration in SiO 2 -rich regions compared to Ni-rich regions. To compare the properties of the samples, all were examined for CO 2 methanation. Even a minor addition of Ru significantly enhanced the conversion of CO 2 and allowed for an excellent CH 4 selectivity (up to 95%) of the methanation process at 400℃. The metallic surface area increased by factors of 8.92 and 4.26 for the Ni–Ru(Ar) and Ni–Ru(H2) samples, respectively, compared to their non-modified counterparts. The proposed approach described in this article demonstrates an effective route for fabricating low-cost catalysts using inexpensive materials such as Ni and SiO 2 , modified with a small amount of Ru, and highlights the feasibility of DIW 3D printing for producing monolithic catalyst structures. This study also emphasizes the importance of an appropriate thermal treatment atmosphere selection, as it may alter the SiO 2 sintering rate. All samples underwent a comprehensive characterization, including chemical and phase composition analysis, microstructural imaging, as well as specific surface area (SSA) examination and CO 2 methanation tests. Graphical abstract Impact statement This work introduces a novel integration of direct ink writing (DIW) three-dimensional printing with post-processing Ru impregnation to develop SiO 2 –Ni catalysts. By combining additive manufacturing with precise control of material composition and structure, the approach enables enhanced CO 2 methanation activity at low ruthenium loadings. The ability to achieve high catalytic efficiency with minimal use of scarce noble metals is both economically and environmentally significant. Furthermore, the influence of sintering atmosphere on catalytic behavior provides new insights into tailoring surface properties through thermal processing. These findings contribute to the development of more sustainable, scalable, and design-flexible catalysts for power-to-gas and carbon utilization technologies. The strategy demonstrated here also highlights the growing potential of digital manufacturing in catalysis and materials design, offering routes toward structurally optimized, application-specific catalytic systems.