Behavior of Lewis and Brönsted surface acidity featured by Ag, Au, Ce, La, Fe, Mn, Pd, Pt, V and W decorated on protonated titanate nanotubes

Abstract

Ag, Au, Ce, La, Fe, Mn, Pd, Pt, V and W nanoparticles were decorated on the surface of titanate nanotubes obtained by hydrothermal treatment. Likewise, the titanate nanotubes with the incorporated active transition, precious and rare earth metals were characterized by XRD, HRTEM, and BET. FTIR-pyridine and UV–Vis were used in order to quantify the acid sites present in different metal catalysts, the main goal of this work.Metal nanoparticles were incorporated in-situ on the surface of the titanate nanotubes by the hydrothermal treatment. The average sizes displayed by the metal nanoparticles were between 1 and 5 nm, finding highly uniform dispersion for all the metals. As a result of the metal incorporation, the acidity of each catalytic system was tuned specially, increasing the number of Brönsted and Lewis sites, which modified significantly the total surface acidity of the 1-D titanate nanotubes.