Applied Catalysis A: General, Vol.454, 74-80, 2013
Metal cations intercalated titanate nanotubes as catalysts for alpha,beta unsaturated esters production
Characterization and catalytic performances of cations (M=Ce4+, La3+, Co2+, Cu2+ or Na+) intercalated titanate nanotubes (MTNT) were performed for alpha,beta unsaturated esters production. Structural properties of the solids were evaluated by transmission electron microscopy (TEM) analysis and X-ray diffraction (XRD), and Raman spectroscopy measurements whereas textural properties were obtained through nitrogen adsorption-desorption isotherms. The transition metals were intercalated in titanate nanotubes by ionic exchange reaction where the Na+ cations were substituted by Ce4+ La3+, Co2+ and Cu2+ ones. Also, the structural characterizations revealed that the ion-exchange processes can favour the formation of nanosized oxides on the TNT surfaces, in some cases. Textural analysis showed high surface area, pore volume and diameters, but a superior catalytic activity and recyclability was only observed for CeTNT and LaTNT catalysts. The improved performance of CeTNT was believed to be related to the presence of Ce4+ cations in the interlamellar region and CeO2 nanosized particles on TNT surface as well. (C) 2013 Elsevier B.V. All rights reserved.