Periodic mesoporous titanium phosphonate spheres for high dispersion of CuOnanoparticles

Abstract

Periodic mesoporous titanium phosphonate spheres are prepared in the presence of surfactant Brij 56 by utilizing sodium salt of ethylene diamine tetra(methylene phosphonic acid) as the coupling molecule. The spherical morphology could be only obtained with the water–ethanol ratio of 75/25. The synthesized hybrids possess periodic mesoporosity with specific surface area of 606 m² g⁻¹ and irregular macrovoids throughout the microspheres, revealed by the measurements of X-ray diffraction, nitrogen adsorption, scanning and transmission electron microscopy. The structure and chemical states of the materials are characterized by chemical analysis, FT-IR, MAS NMR, XPS and thermogravimetric analysis, indicating the homogeneous integrity of organic groups inside the hybrid framework, which allows Cu²⁺ ions extensively coordinated with these organic ligands. The monolayer adsorption behavior of Cu²⁺ ions is confirmed, and further calcination of the Cu²⁺ ion-dispersed matrix results in the highly dispersed CuO active components on the pore surface of mesoporous titanium phosphonates. The H₂-TPR analysis and catalytic CO oxidation testing prove that the CuO nanoparticles, dispersed on either hybrid or inorganic supports, prepared by this coordination and calcination strategy, possess high oxidation activity, making them promising catalysts for potential environmental applications.