The effect of sintering temperature on mesoporous structure of WO3 doped TiO2 powders

Abstract

In this study, WO 3 doped TiO 2 powders were synthesized via sol-gel method combined with a hydrothermal process. The effect of sintering temperature on mesoporous structure and catalytic activities of these powders were investigated. The physical analysis via X-ray diffraction indicates that prepared samples are a mixture of anatase and rutile TiO 2 phases. X-ray peak analysis is used to evaluate the crystallite size and lattice strain by the Williamson-Hall analysis. Considering all the reflections of the anatase phase the lattice strain ranging from c = 9.505 to c = 9.548 is calculated, suggesting that microstrain decreases when calcination temperature increases. N 2 adsorption-desorption analysis shows that the surface area and pore volume decrease with increasing temperature and that WO x-TiO 2 powders primarily consist of mesopores. Sintering temperature induced a change in textural properties causing a systematic shift towards larger mesopores. Simultaneously, photoactivity in decolorization of methyl orange increases with increasing calcination temperature up to 700 °C, followed by significant decrease with its further increase.

New CeO2–TiO2, WO3–TiO2 and WO3–CeO2–TiO2 mesoporous aerogel catalysts for the low temperature selective catalytic reduction of NO by NH3

“…1 . According to the literature reports, this phenomen could be explained by (i) the agglomeration of the metal clusters to form larger particle size [36] or (ii) a sintering which probably happened in the WO 3 -TiO 2 sample and has led to the increase of the TiO 2 grain size [37].…”

“…It is important to note that the decrease of the surface area of TiO 2 after Ce and/or W incorporation can be explained by the blockage of some pores of titania carrier by the supported active species [32,33]. According to Petrović et al [37], the growth of the TiO 2 crystallites size after W addition contributes also to the decrease of the specific surface area and total pore volume of WO 3 -TiO 2 solid which is characterized by the lowest values of textural parameters (S BET and V PT , table 2) but by the highest one of the TiO 2 crystallites size (table 1).…”

Morphology control of SrBi2Nb2O9 prepared by a modified chemical method

“…The Williamson-Hall method used to understand the contributions of lattice strain and crystalline size to the XRD peak [10]. The different variants of the method such as an isotropic strain model, anisotropic strain model and uniform deformation energy density model are used may be useful.…”

Cost analysis of T6 induction heat treatment for the aluminum-copper powder metal compacts

“…P/M compacts are produced by mixing pure or alloy powders, being compressed within a mould and being heated in order to allow the metal powders to form a metallurgical bond [3]. Sintering [4,5] is the method of producing components, of which density can be kept under control, and of which resistance & integrity are formed through the implementation of thermal energy to the metal powders in a temperature under the fusion temperature. When thermal energy is applied on compressed metal powder, the component condensates, and the average particle size level increases; this condensation and the increase in the particle size is named as sintering [6].…”