Effect of TiO2 crystallite size on the dispersion of Co on nanocrystalline TiO2

Abstract

Nanocrystalline TiO 2 powders with average crystallite sizes of 9-15 nm were synthesized by the solvothermal method and employed as supports for Co catalysts. The value of H 2 chemisorption/specific surface area of Co/TiO 2 increased significantly with increasing TiO 2 crystallite size. It was suggested that the higher amount of Ti 3+ surface defects on the larger crystalline TiO 2 resulted in a stronger interaction between Co and TiO 2 , hence, higher dispersion of Co was obtained.

Improved catalytic performance of Pd/TiO2 in the selective hydrogenation of acetylene by using H2-treated sol–gel TiO2

“…In our previous work [32], a larger amount of Ti 3+ surface defects on the solvothermal-derived nanocrystalline TiO 2 was also found to result in a stronger interaction between Co and TiO 2 and then a higher Co dispersion.…”

Effect of surface Ti3+ on the sol–gel derived TiO2 in the selective acetylene hydrogenation on Pd/TiO2 catalysts

“…In the literature, the amount of surface Ti 3+ sites decreased with increasing percentages of rutile phase in the TiO 2 resulting in lower Pd dispersion [13]. Kongsuebchart et al [14] has reported that the presence of surface Ti 3+ on the TiO 2 prepared by the solvothermal method was useful for preparation of Co/TiO 2 catalysts with high Co dispersion. In addition, the presence of Ti 3+ in contact with Pd affected the metal-support interaction and higher ethylene selectivity was obtained in the selective acetylene hydrogenation over Pd/TiO 2 [4].…”

Effect of TiO2 Crystallite Size on the Activity of CO Oxidation

“…In the light of our previous studies for Co/TiO 2 Fischer-Tropsh, it is suggested that the presence of Ti 3? sites on the TiO 2 surface can inhibit agglomeration of metal particles during impregnation, calcination, and reduction steps so that higher metal dispersion was obtained [7,8]. Aggregation of TiO 2 nanoparticles may also have influence upon the reduced surface Ti 3?…”

“…A previous study from our group reported a comparison of nanocrystalline pure anatase TiO 2 prepared by solvothermal method with average crystallite sizes 9 and 15 nm as supports for Co/TiO 2 catalysts in Fischer-Tropsch reaction. It was found that the nanocrystalline TiO 2 support with larger crystallite size resulted in higher chemisorption abilities of Co/TiO 2 catalysts [7]. The increase of metal dispersion was explained by the presence of Ti 3?…”