Porous catalyst support from clay-precipitated calcium carbonate for carbon nanomaterials growth

Abstract

Currently, porous materials were widely used as catalyst supports, adsorption of gases or liquid, and gas sensors. In this research, the fabrication of catalyst support utilised clay with controlled amounts of precipitated calcium carbonate (PCC) at 10 wt.%, 15 wt.%, 20 wt.%, and 25 wt.% via a polymeric foam replication method. A mixture of clay, precipitated calcium carbonate, and distilled water were ball milled for 24 hours and 48 hours milling durations in order to form ceramic slurries. After the impregnation process of polymeric foam into ceramic slurries, the green ceramic was dried and sintered at 1250°C for 2 hours holding time. The main objectives of this research are to study the effects of precipitated calcium carbonate additions and different milling durations on the physical and mechanical properties of the catalyst support. The sample that was fabricated with 25 wt.% of precipitated calcium carbonate and milled at 48 hours was found to have the highest compressive strength which at 1.6 MPa. Besides, one-way analysis of variance (ANOVA) showed that the increase between 10 wt.% and 25 wt.% of PCC has significantly increased the strength of the catalyst support and the coefficient of determination (R2) at 0.92. The increase of the mechanical strength was attributed to the transformation of new phases such as anorthite (2CaAl2Si2O8), mullite (3Al2O3·2SiO2), and gehlenite (3Ca2Al2SiO7). On the other hand, foam density would increase when the percentage of porosity decreased.