Sol-gel synthesis of pure and copper oxide coated mesoporous alumina granular particles

A modified oil-drop sol-gel process is reported for synthesis of mesoporous spherical γ-Al₂O₃ granular particles and CuO-coated γ-Al₂O₃ granular particles of 1-3 mm in diameter. Various parameters affecting the granulation process were studied, and the optimum values of these parameters were identified for reproducible synthesis of the alumina granular particles. Under the optimum synthesis conditions, CuO-coated γ-Al₂O₃ granular particles could be synthesized directly from the pseudo-boehmite sol doped with Cu(NO₃)₂ by a solution-sol mixing method. The CuO-coated γ-Al₂O₃ granular particles prepared by the solution-sol mixing coating method exhibit better mechanical and sulfation properties than the similar sorbents prepared by the wet-impregnation method. The sol-gel derived granular CuO-coated γ-Al₂O₃ sorbents prepared by both coating methods have the same microstructure at lower CuO loading.