Synthesis of Nanophased Metal Oxides in Supercritical Water: Catalysts for Biomass Conversion
Abstract:Nanoparticles of zinc oxide-based materials (ZnO, ZnAl2O4) with various morphologies were synthesized in supercritical water (SCW) with a flow-type apparatus and in sub- and supercritical water with a batch reactor. In the flow-type apparatus, smaller particles were obtained. Depending on the precursors, the morphology of crystallites is rod, hexagonal, or rectangular shaped. ZnAl2O4 was synthesized with a high specific surface area (SBET) reaching 210 m2/g and nanocrystallite sizes ≤10 nm. The KOH concentration played a major role in the formation of ZnO and ZnAl2O4 phases. Then, the synthesized materials were used as catalysts for the biomass conversion by the oxidation process to produce hydrogen.
Document Type: Research Article
Affiliations: 1: Research Center of Supercritical Fluid Technology, Tohoku University, Sendai 980-8579, Japan 2: Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Chiba 275-8575, Japan
Publication date: October 1, 2006