mesoporous TiO2, gold nanoparticle, homocoupling reaction, recyclable catalyst, deposition precipitation
This report describes the systematic incorporation of gold nanoparticles (AuNPs) onto mesoporous TiO2 (MPT) particles without strong attractive forces to efficiently serve as reactive and recyclable catalysts in the homocoupling of arylboronic acid in green reaction conditions. Unlike using nonporous TiO2 particles and conventional SiO2 particles as supporting materials, the employment of MPT particles significantly improves the loading efficiency of AuNPs. The incorporated AuNPs are less than 10 nm in diameter, regardless of the amount of applied gold ions, and their surfaces, free from any modifiers, act as highly reactive catalytic sites to notably improve the yields in the homocoupling reaction. The overall physical properties of the AuNPs integrated onto the MPT particles are thoroughly examined as functions of the gold content, and their catalytic functions, including the rate of reaction, activation energy, and recyclability, are also evaluated. While the rate of reaction slightly increases with the improved loading efficiency of AuNPs, the apparent activation energies do not clearly show any correlation with the size or distribution of the AuNPs under our reaction conditions. Understanding the formation of these types of composite particles and their catalytic functions could lead to the development of highly practical, quasi-homogeneous catalysts in environmentally friendly reaction conditions.
This research was funded by the Technology Innovation Program (20010683, Development of the traction motor and elementary manufacturing technology for 70 kW xEV using low cost permanent magnet) funded by the Ministry of Trade, Industry, and Energy (MOTIE, Korea).
Hou, Jian; Jang, Wongi; Yun, Jaehan; Egemole, Franklin Obinna; Geng, Dianguo; Byun, Hongsik; Kang, Dong-Woo; and Kim, Jun-Hyun, "Systematic Incorporation of Gold Nanoparticles onto Mesoporous Titanium Oxide Particles for Green Catalysts" (2021). Faculty Publications – Chemistry. 9.