Efficient non-volatile organogold complex for TiO2-supported gold cluster catalysts: Preparation and catalytic activity for CO oxidation

Gold nanoparticles supported on titania (Au/TiO2) catalysts were prepared by solid grinding (SG) method using a halide-free nonvolatile organogold complex, bis(phenyl)boroxinato(4-tolylpyridyl)gold(III), abbreviated as AuBO, followed by calcination. Density functional theory (DFT) calculation revealed that AuBO was adsorbed on TiO2 by hydrogen bonding with the surface hydroxy group of TiO2 and that the adsorption energy was lower than those of other gold precursors. The obtained catalyst (AuBO/TiO2) showed higher catalytic activity for CO oxidation than did Au/TiO2 prepared by conventional deposition-precipitation method and by SG using other organogold complexes. Furthermore, grinding of the gold precursor with potassium tert-butoxide followed by calcination (AuBO/K-TiO2) improved the catalytic activity and 100% CO conversion reached at - 23 degrees C (temperature at which 50% CO conversion occurs, T-1/2 = - 39 degrees C) as compared to AuBO/TiO2 (T-1/2 = - 28 degrees C). Potassium tert-butoxide facilitated the decomposition of AuBO adsorbed on TiO2, and increased surface basicity contributed to the improved catalytic activity. AuBO/K-TiO2 also exhibited high catalyst stability for CO oxidation at room temperature. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

Gold nanoparticles supported on titania catalysts were prepared using the solid grinding method, and the catalytic activity was improved by treatment with potassium tert-butoxide. The catalyst exhibited high catalytic activity and stability for CO oxidation.