Comparison of Direct Ink Writing and Binder Jetting for additive manufacturing of Pt/Al2O3 catalysts for the dehydrogenation of perhydro-dibenzyltoluene
Hanh My Bui, Paula F. Großmann, Anne Berger, Alexander Seidel, Markus Tonigold, N. Szesni, Richard W. Fischer, Bernhard Rieger, Olaf Hinrichsen
Abstract
Two additive manufacturing (AM) techniques, namely extrusion-based Direct Ink Writing (DIW) and powder-based Binder Jetting (BJ), were thoroughly compared to assess their respective advantages and drawbacks for catalyst shaping. The 3D printed monolithic Al 2 O 3 supports were wet impregnated with H 3 Pt(SO 3 ) 2 (OH) and tested for the dehydrogenation of perhydro-dibenzyltoluene (18H-DBT), a liquid organic hydrogen carrier (LOHC). The supports were analyzed regarding their specific surface area, compression strength , shrinkage behavior and pore size distribution with calcination temperatures ranging from 600 - 1200 °C as well as 3D print specific characteristics. Benefiting the liquid phase reaction, pore diameters below 26 nm were diminished above T calc = 1050 °C, revealing a BET surface area of 26 m 2 /g for BJ and 11 m 2 /g for DIW printed supports. Furthermore, increasing the impregnation duration from 0.5 h to 12 h showed increased Pt loading, larger metal particles, and a deeper penetration into the support. Most notably, for BJ the Pt loading is generally higher due to higher meso- and macroporosity of the support. Catalytic 18H-DBT dehydrogenation with powder and monolithic catalysts showed equal dehydrogenation rates with both 3D printing methods, respectively. The achieved Pt productivity was about 4 . 3 g H 2 g Pt − 1 min − 1 for powder tests and 2 . 7 g H 2 g Pt − 1 min − 1 for monolithic pellets.