(435f) Catalytic Honeycomb Manufacturing By Three Dimensional Assembly of Hierarchical Co3O4 Nanoarray for High Performance NO Oxidation

A novel noble metal free catalytic honeycomb has been successfully developed by incorporating hierarchically three dimensional Co₃O₄ nanoarrays into monolithic honeycomb with a facile one pot hydrothermal strategy followed by ambient annealing^1-3. The morphology evolution with various precursors has led to Co₃O₄ nanostructures of different sizes and shapes. The Co₃O₄ nanoarrays-based honeycomb exhibits a remarkable efficiency as high as 80% for catalytic NO oxidation at high space velocity (~50,000 h^-1) but relatively low temperature (~275 ^oC).  The nanoscale manufacturing of Co₃O₄ nanowire arrays has successfully improved the catalytic capability compared with the wash-coated Co₃O₄ powder. The three dimensional ordered geometric arrangement of nanoscale building blocks is thus believed to facilitate the gas solid interaction and efficient diffusion, which are important for catalytic reactions. Detailed investigation on grain size, surface area, pore size as well as surface chemistry comes to the conclusion that Co³⁺ on surface determines the catalytic activity. The nanocatalysts maintain high efficiency during cyclic tests and show little degradation in catalytic activity under both isothermal and temperature fluctuation condition. This work opens up new opportunity for fabricating catalytic device with well controlled nanostructure geometry and large scale spatial arrangement. In addition, the as-prepared ultraefficient but cost effective nanocatalytic honeycomb will serve as a good candidate in environmental applications. Specifically, the high performance NO conversion into NO₂ will potentially increase the efficiency of current nitrogen oxide removal technology.

Reference

[1] Y. Guo^†, Z. Ren^†, (^†equally contributed) W. Xiao, C. Liu, H. Sharma, H. Gao, A. Mhadeshwar and P. X. Gao, Nano Energy, 2013, in press.

[2] Z. Ren, Y. Guo, Z. Zhang, C. Liu and P. X. Gao, submitted, 2013.

[3] P. X. Gao, Y. Guo, Z. Ren and Z. Zhang, US non-provisional patent filed, (2012)