Direct-ink-write printing performance of zeolite catalysts with porous structures

Porous zeolite materials printed by direct-ink-writing (DIW) feature high mechanical strength and excellent mass and heat transfer performance, which can improve catalytic reaction performance effectively. Aiming at prob-lems such as the shearing thinning appearing in ink materials and the low formation accuracy of structured catalysts in the DIW process, this paper studies the effects of the process parameters of DIW (including solid ink content, nozzle diameter, nozzle height, printing speed, extrusion pressure, etc.) on 3D printing processes such as extrusion and formation. In addition, it analyzes the main factors affecting printing accuracy and stability, attempting to improve the performance of DIW in printing structured catalysts through process optimization. Specifically, we designed and prepared a porous zeolite catalyst combining the conditions of catalytic reaction and DIW process and studied the printing accuracy, surface morphology, strength and other mechanical prop-erties of the catalyst and tested the performance of structured catalysts in xylene isomerization. The experimental results show that the zeolite catalyst demonstrated fine catalytic performance and mechanical strength when the ink solid content, the nozzle diameter and the printing pressure P were 46 wt%, 600 mu m and 0.35 MPa respectively. Under this circumstance, and the conversion rate of ethylbenzene could reach to 51.31%, which is 71% higher compared with traditional extrusion catalysts, and the compression strength could reach to 11 MPa.