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| Hydrogenation of polystyrene (PS) to produce hydrogenated polystyrene, also known as polycyclohexylethylene, is an important polymer modification process to improved heat and UV resistance of PS. Owning to the large size of PS coils and high viscosity of the system, macroporous ceramic foam (CF) had good industrial potential. However, the CF usually possessed low specific surface area (<1 m2/g) due to high-temperature sintering. In this paper, the SiO2-TiO2 CF (STCF) was prepared using synthetic template replica method, and further HF-etching was applied to increase the specific surface area. The effect of HF etching on the mechanical and structural properties of STCF was investigated by strength test, SEM, EDX, and XRD, respectively. By optimizing the treatment time, HF-etching could remove the SiO2 on the surface of CF sample while the SiO2 inside the struts was remained, leaving interspaces on the etched CFs struts (0.5 - 1.0 μm). The obtained 0.1STCF-HF5 with increased specific surface area could facilitate the dispersion of Pd. The Pd-supported HF-etched STCF catalyst exhibited enhanced hydrogenation activity with negliable internal diffusion of PS coils. |
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| Keywords:Catalytic reaction engineering; Ceramic foam; Polystyrene hydrogenation; HF-etching |
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