Catalytic activity of Au/TiO2 and Pt/TiO2 nanocatalysts prepared with arc plasma deposition under CO oxidation

We report the catalytic activity of Au/TiO2 and Pt/TiO2 nanocatalysts under CO oxidation fabricated by arc plasma deposition (APD), which is a facile dry process involving no organic materials. Using APD, the catalyst nanoparticles were well dispersed on the TiO2 powder with an average particle size of 2–4 nm, well below that of nanoparticles prepared by the sol–gel method (10 nm). We found that the average particle size of the dispersed gold nanoparticles can be controlled by changing the plasma discharge voltage of APD. Accordingly, the amount of gold loaded on the TiO2 powder increased as the discharge voltage increased, but the specific surface area of the Au/TiO2 samples decreased. As for catalytic reactivity, Au/TiO2 showed a higher catalytic activity than Pt/TiO2 in CO oxidation. The catalytic activity of the Au/TiO2 samples showed size dependence where higher catalytic activity occurred on smaller gold nanoparticles. This study suggests that APD is a simple way to fabricate catalytically active nanocatalysts.151551sciescopu

Support Effect of Arc Plasma Deposited Pt Nanoparticles/TiO₂ Substrate on Catalytic Activity of CO Oxidation

The smart design of nanocatalysts can improve the catalytic activity of transition metals on reducible oxide supports, such as titania, via strong metal–support interactions. In this work, we investigated two-dimensional Pt nanoparticle/titania catalytic systems under the CO oxidation reaction. Arc plasma deposition (APD) and metal impregnation techniques were employed to achieve Pt nanoparticle deposition on titania supports, which were prepared by multitarget sputtering and sol–gel techniques. APD Pt nanoparticles with an average size of 2.7 nm were deposited on sputtered and sol–gel-prepared titania films to assess the role of the titania support on the catalytic activity of Pt under CO oxidation. In order to study the nature of the dispersed metallic phase and its effect on the activity of the catalytic CO oxidation reaction, Pt nanoparticles were deposited in varying surface coverages on sputtered titania films using arc plasma deposition. Our results show an enhanced activity of Pt nanoparticles when the nanoparticle/titania interfaces are exposed. APD Pt shows superior catalytic activity under CO oxidation, as compared to impregnated Pt nanoparticles, due to the catalytically active nature of the mild surface oxidation and the active Pt metal, suggesting that APD can be used for large-scale synthesis of active metal nanocatalysts