Spray pyrolysis-derived MoO3@Al2O3@TiO2 core-shell structures with enhanced hydrodeoxygenation performance

Abstract

Developing highly active and stable hydrodeoxygenation (HDO) catalysts is an industrial challenge. In this work, γ-Al2O3 microspheres incorporating high levels of Mo catalyst (30 wt%; MoO3@Al2O3) were effectively and rapidly prepared by ultrasonic-assisted spray pyrolysis. The MoO3@Al2O3 microspheres were then decorated by a hydrophobic TiO2 layer to obtain core–shell-structured microspheres dubbed MoO3@Al2O3@TiO2. HDO experiments revealed that catalysis by reduced MoO3@Al2O3@TiO2 microspheres afforded ~96% palmitic acid (PA) conversion and ~ 67% hydrocarbon selectivity, surpassing the uncoated catalyst. Furthermore, the prepared TiO2-coated MoO3@Al2O3 microspheres retained excellent HDO catalytic activity under water-containing feed for 24 h. This study's results suggest that combining spray pyrolysis and coating with a TiO2 shell produces a synergetic effect that enhances the catalyst's activity and stability.