Title : Catalytic CO? Hydrogenation over additively manufactured metal structures under ambient conditions
Abstract:
Catalytic hydrogenation of carbon dioxide (CO?) is considered as a promising approach of converting CO? into valuable chemicals and fuels, however developing an active catalyst remains a challenge. This present work demonstrated the application of NiGa intermetallic phase functionalized 3D printed structured catalysts (Inconel 625, TiAlV, and Brass) for the first time towards CO? hydrogenation. 3D printed metallic structures were functionalized with NiGa intermetallic phase, by dip coating and catalysts were activated by reducing under hydrogen atmosphere at 550 °C to obtain the active intermetallic phase. CO? hydrogenation over these catalysts were screened in a tubular fixed-bed stainless steel reactor at 300 °C, 400°C, and 500 °C under atmospheric pressure for continuous 5 hours. Reaction products were analyzed using a PerkinElmer GC-TCD. The catalytic performance showed a distinct temperature-dependent selectivity: CO was predominantly formed at lower temperatures via the reverse water-gas shift (RWGS) reaction, while CH? production became dominant at higher temperatures due to enhanced CO? methanation activity. The use of 3D printed open framework metallic structures as structured supports provided several advantages, including improved heat and mass transfer, reduced diffusion limitations, and enhanced structural stability during reaction. Among the tested supports, variations in thermal conductivity and surface properties were found to influence product distribution and catalyst stability. Overall, the results demonstrated that NiGa catalysts supported on 3D metallic frameworks present an effective and scalable route for selective CO? hydrogenation at ambient conditions. The study underscores the potential of intermetallic catalysts on engineered monolithic architectures as new generation of catalysts, offering valuable insights for the development of advanced catalytic systems for sustainable CO? utilization.
