Three-dimensionally ordered mesoporous Co3O4-supported Au–Pd alloy nanoparticles: High-performance catalysts for methane combustion

•AuyPd/meso-Co3O4 is prepared by polyvinyl alcohol-protected reduction.•AuyPd alloy nanoparticles are well dispersed on the surface of mesoporous Co3O4.•There is a strong interaction between AuyPd alloy and meso-Co3O4.•2.94Au0.50Pd/meso-Co3O4 shows excellent catalytic activity for methane combustion.•2.94Au0.50Pd/meso-Co3O4 exhibits good tolerance of CO2 and SO2.

Three-dimensionally ordered mesoporous Co3O4 (meso-Co3O4) and its supported Au, Pd, and Au–Pd alloy (xAuyPd/meso-Co3O4; x = 0.43–2.94 wt%; Au/Pd molar ratio (y) = 0.43–0.50) nanocatalysts were prepared using the KIT-6-templating and polyvinyl alcohol-protected reduction methods, respectively. It is found that the meso-Co3O4 with a high surface area of 106 m2/g was cubic in crystal structure and the noble metal nanoparticles (NPs) with a size of 2.7–4.5 nm were uniformly dispersed on the surface of meso-Co3O4. The 2.94Au0.50Pd/meso-Co3O4 sample performed the best for methane combustion, showing the T10%, T50%, and T90% (temperatures required for achieving methane conversions of 10%, 50%, and 90%) of 230, 280, and 324 °C at a space velocity of 20,000 mL/(g h) and the lowest apparent activation energy of 44.4 kJ/mol. Furthermore, the effects of CO2, SO2, and H2O addition on the catalytic stability of 2.94Au0.50Pd/meso-Co3O4 were also examined. It is concluded that the excellent catalytic performance of 2.94Au0.50Pd/meso-Co3O4 was associated with its porous structure, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between Au–Pd alloy NPs and meso-Co3O4.

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