Pt/Co3O4/3DOM Al2O3: Highly effective catalysts for toluene combustion

Three-dimensionally ordered macro-/mesoporous alumina (3DOM Al2O3)-supported cobalt oxide and platinum nanocatalysts (xPt/yCo3O4/3DOM Al2O3, Pt mass fraction (x%) = 0−1.4%, Co3O4 mass fraction (y%) = 0−9.2%) were prepared using poly(methyl methacrylate) templating, incipient wetness impregnation and polyvinyl alcohol-protected reduction. The resulting xPt/yCo3O4/3DOM Al2O3 samples displayed a high-quality 3DOM architecture with macropores (180–200 nm in diameter) and mesopores (4–6 nm in diameter) together with surface areas in the range of 94 to 102 m2/g. Using these techniques, Co3O4 nanoparticles (NPs, 18.3 nm) were loaded on the 3DOM Al2O3 surface, after which Pt NPs (2.3–2.5 nm) were uniformly dispersed on the yCo3O4/3DOM Al2O3. The 1.3Pt/8.9Co3O4/3DOM Al2O3 exhibited the best performance for toluene oxidation, with a T90% value (the temperature required to achieve 90% toluene conversion) of 160 °C at a space velocity of 20000 mL g−1 h−1. It is concluded that the excellent catalytic performance of the 1.3Pt/8.9Co3O4/3DOM Al2O3 is owing to well-dispersed Pt NPs, the high concentration of adsorbed oxygen species, good low-temperature reducibility, and strong interaction between the Pt and Co3O4 NPs, as well as the unique bimodal porous structure of the support.

Graphical AbstractThe xPt/yCo3O4/3DOM Al2O3 nanocatalysts perform well in toluene combustion. The well-dispersed Pt nanoparticles, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between Pt and Co3O4 account for the excellent activity of 1.3Pt/8.9Co3O4/3DOM Al2O3.Figure optionsDownload full-size imageDownload as PowerPoint slide