Solvent-Free Catalytic Oxidation of Benzyl Alcohol over Au-Pd Bimetal Deposited on TiO2: Comparison of Rutile, Brookite, and Anatase

Xiaoliang Li; Jiangjiang Feng; Jia Sun; Zhe Wang; Wei Zhao

doi:10.1186/s11671-019-3211-8

Solvent-Free Catalytic Oxidation of Benzyl Alcohol over Au-Pd Bimetal Deposited on TiO₂: Comparison of Rutile, Brookite, and Anatase

Nanoscale Res Lett. 2019 Dec 27;14(1):394. doi: 10.1186/s11671-019-3211-8.

Authors

Xiaoliang Li¹, Jiangjiang Feng², Jia Sun³, Zhe Wang², Wei Zhao⁴

Affiliations

¹ State Key Laboratory Breeding Base of Coal Science and Technology Co-founded by Shanxi Province and the Ministry of Science and Technology, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, People's Republic of China. lixiaoliang@tyut.edu.cn.
² State Key Laboratory Breeding Base of Coal Science and Technology Co-founded by Shanxi Province and the Ministry of Science and Technology, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, People's Republic of China.
³ Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff, CF10 3AT, UK.
⁴ State Key Laboratory Breeding Base of Coal Science and Technology Co-founded by Shanxi Province and the Ministry of Science and Technology, Taiyuan University of Technology, Taiyuan, 030024, Shanxi, People's Republic of China. zhaowei@tyut.edu.cn.

Abstract

TiO₂ (P25)-supported Au-Pd bimetal nanoparticles displayed excellent performance in the solvent-free benzyl alcohol catalytic oxidation. However, little research attention has been paid to investigate the effects of TiO₂ form on the catalytic activity of Au-Pd/TiO₂. In the present research, rutile, brookite, and anatase TiO₂ were successfully synthesized and subsequently applied as the carrier to load Au-Pd nanoparticles by the deposition-precipitation method. The experimental results indicated that the benzyl alcohol conversion employing the rutile TiO₂-supported Au-Pd catalyst is higher than the conversion of anatase and brookite TiO₂-loaded Au-Pd catalysts. However, the Au-Pd/TiO₂-rutile displayed the lowest and highest selectivity toward benzaldehyde and toluene, respectively. ICP-AES, XRD, XPS, and TEM were conducted to characterize these catalysts. The corresponding experimental results revealed that the excellent performance of Au-Pd/TiO₂-rutile catalyst was attributed to both the smaller Au-Pd nanoparticle size distribution and the higher concentrations of O_α and Pd²⁺ species on the catalyst surface. In the recycle experiments, the Au-Pd/TiO₂-rutile catalyst displayed lower reaction stability compared with the Au-Pd/TiO₂-anatase and Au-Pd/TiO₂-brookite, which might be due to the coverage of larger amount of aldehyde products on the surface.

Keywords: Anatase; Au-Pd nanoparticles; Benzyl alcohol oxidation; Brookite; Rutile; Solvent-free; TiO2 crystal form.

Abstract

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