Morphology and crystal structure of CeO2-modified mesoporous ZrO2 powders prepared by sol–gel method

Abstract

Mesoporous ZrO2 powder modified by CeO2 has been prepared by sol–gel method combined with novel heat-treatment without any templates. The morphology and crystal structure were characterized by Fourier transform infrared spectrophotometer (FT-IR), thermal gravimetry/differential thermal analysis (TG/DTA), X-ray diffraction (XRD), Raman spectroscope, N2 absorption–desorption, scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM). It was demonstrated that the morphologies and crystal structures were varied with the CeO2 content and calcination temperatures. Some circular grooves with diameter about 300–500nm and thickness of 150–200nm were observed for 30mol% CeO2 modified samples. Tetragonal ZrO2 and cubic (Ce,Zr)O2 solid solution were in turn observed with CeO2 content increasing. The oxygen storage capacity (OSC) of the mesoporous powders was determined by thermalgravimetry (TG) under cyclic thermal treatments.