Effectiveness of the 3D-printing procedure in the synthesis of hybrid catalysts for the direct hydrogenation of CO2 into dimethyl ether,

This work highlights the effectiveness of an unconventional synthesis of hybrid systems for the direct hydrogenation of carbon dioxide into dimethyl ether (DME), based on micro-extrusion of a ink-like catalytic paste by a robocasting procedure. Due to the possibility to exert a fine control over the structure, surface and geometric architecture, the adopted printing technique really ensures a superior management of heat and mass constraints in respect of the conventional powdered catalysts, the catalyst functionality resulting to be tightly dependent on the cooperation between metal-oxide and acidic phase. Additionally, the accessibility both of the CO2 activation and methanol (MeOH) dehydration sites over the hybrid micro-extruded catalyst most importantly affects the catalytic performance, as suggested by the values of turnover frequency of CO2 conversion and DME formation pointing out the need for a favorable exposure of chemisorption sites of different nature to enhance the specific reactivity.