Amines supported on porous solid materials have a high CO₂ adsorption capacity and low regeneration temperature. However, the high amine load on such substrates and the substrate itself may lead to substantial pressure drop across the reactor. Herein, we compare the CO₂ adsorption capacity and pressure drop of fumed silica powder to 3D-printed monolithic fumed silica structures, both functionalized by polyethylenimine (PEI), and find a drastically reduced pressure drop for 3D-printed substrates (0.01 bar vs. 0.76 bar) in the sorption bed with equal CO₂ adsorption capacity. Furthermore, the effect of 3D-printing nozzle diameter and PEI loading on the adsorption capacity are investigated and the highest capacities (2.0 mmol/g at 25 °C with 5000 ppm CO₂) are achieved with 0.4 mm nozzle size and 34 wt% PEI loading. These high capacities are achieved since the 3D printing and subsequent sintering (700 °C) of monolithic samples does not compromise the surface area of the fumed silica. Finally, the comparison between 3D-printed monoliths and extruded granulate of varying diameter reveals that the ordered channel system of 3D-printed structures is superior to randomly oriented granulate in terms of CO₂ adsorption capacity.

MoSi₂ is an electrically conductive material with numerous applications mostly in high‐temperature environments. Herein, the production of MoSi₂‐containing resistive heating elements by ceramic injection molding (CIM) is described. The sintered parts consist of MoSi₂ particles embedded in a matrix of vitrified feldspar and Al₂O₃. The conductivity of sintered parts can be tuned precisely by varying the content of the conductive phase. For the development of the injection‐molding feedstock, four binder systems are evaluated. The corresponding feedstocks are injection molded into different geometries in traditional molds as well as in additively manufactured, soluble molds. For each feedstock, a debinding and sintering routine is elaborated based on thermogravimetric measurements. Higher debinding temperature leads to more oxidation of MoSi₂ and less conductive samples. Therefore, the conductivity as well as density of sintered parts is used to evaluate the applicability of the feedstocks. Finally, glow tests prove that MoSi₂/Al₂O₃/feldspar composite parts can be used as heating elements and by combining infrared temperature measurement data with computational simulations important material data such as thermal and electrical conductivity and thermal capacity can be obtained reliably.

The cover illustrates the sintering of MoSi₂/Al₂O₃/Feldspar heating elements fabricated by injection molding, thus allowing more complex geometries and more economical heating element production, see the article number 2100517 by Dirk Penner and co-workers. Different binder systems are investigated and heating elements of various shapes as shown in the illustration are produced and tested. (Cover design: René Wick-Joliat)