3D printed Ni/Al2O3 based catalysts for CO2 methanation - a comparative and operando XRD-CT study

Abstract

Ni-alumina-based catalysts were directly 3D printed into highly adaptable monolithic/multichannel systems and evaluated for CO2 methanation. By employing emerging 3D printing technologies for catalytic reactor design such as 3D fibre deposition (also referred to as direct write or microextrusion), we developed optimised techniques for tailoring both the support's macroand microstructure, as well as its active particle precursor distribution. A comparison was made between 3D printed commercial catalysts, Ni-alumina based catalysts and their conventional counterpart, packed beds of beads and pellet. Excellent CO2 conversions and selectivity to methane were achieved for the 3D printed commercial catalyst (95,75 and 95,63 % respectively) with stability of over 100 h. The structure-activity relationship of both the commercial and in-house 3D printed catalysts was explored under typical conditions for CO2 hydrogenation to CH4, using operando 'chemical imaging', namely X-Ray Diffraction Computed Tomography (XRD-CT). The 3D printed commercial catalyst showed a more homogenous distribution of the active Ni species compared to the in-house prepared catalyst. For the first time, the results from these comparative characterisation studies gave detailed insight into the fidelity of the direct printing method, revealing the spatial variation in physico-chemical properties (such as phase and size) under operating conditions.

3D Printed Palladium Catalyst for Suzuki‐Miyaura Cross‐coupling Reactions

“…The technology of additive manufacturing, broadly known as three‐dimensional (3d) printing, has been evolving extensively in the last decades, and recently catalytically active 3d printed objects started to emerge . Indeed, 3d printing provides potential for creating objects not only with desired catalytic properties, but at the same time with required shapes, e. g. for batch or flow reactors with heterogeneous solid catalysts.…”

“…Indeed, 3d printing provides potential for creating objects not only with desired catalytic properties, but at the same time with required shapes, e. g. for batch or flow reactors with heterogeneous solid catalysts. A number of reports emerged recently on new catalysts for various reactions, produced by 3d printing with and without chemical post‐processing of the printed objects. Among these reports, the majority utilizes fused deposition modelling (FDM) or robocasting, selective laser melting (SLM), and in some cases stereolithography (SL) methods.…”

Modern scaffolding strategies based on naturally pre-fabricated 3D biomaterials of poriferan origin

“…Open-cell foams offer remarkable properties such as a large external surface area, a high mechanical strength and a high porosity; moreover, they guarantee accessibility to the active centers and a low resulting pressure drop [28][29][30]. Open-cell sponge-like catalysts were applied for Fischer-Tropsch synthesis [31], water disinfection by photocatalytic process [32], partial oxidation of methanol [33], CO 2 methanation [34] and many others. Naturally pre-fabricated siliceous skeletal frameworks of glass sponges seem to have all the necessary properties including high thermal and chemical stability as well as defined pore size and cell geometry ensuring good mass transport, which makes them ideal candidates for catalyst support.…”

Electrochemical Reduction of Carbon Dioxide on 3D Printed Electrodes

“…Miramontes et al [66] and Bolton et al [67] succeeded in intensifying the process of CO 2 absorption by amines using 3D printed packing devices. Middelkoop et al [68] printed monolithic Ni/Al 2 O 3 composites and employed them as catalysts in the reduction of carbon dioxide by hydrogen producing methane.…”