High combustion activity of CH4 and catalluminescence properties of CO oxidation over porous Co3O4 nanorods

The highly porous Co3O4 nanorods are prepared by a simple hydrothermal method, in which CO(NH2)2 is employed as precipitating agent, and K60 (PVP, polyvinylpyrrolidone) is used as surfactant to improve the stability of the nanoparticles. For comparison, the bulk Co3O4 is prepared by thermal decomposition of cobalt nitrate. The samples are characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (ED), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, N2 adsorption, Thermogravimetric analysis (TG), H2-temperature programmed reduction (TPR), CO-, CH4-, and O2-temperature programmed desorption (TPD). The catalluminescence (CTL) and catalytic properties of the samples are investigated extensively. The results show that the Co3O4 nanorods are composed of nanoparticles, and have a large number of pores with a narrow pore size distribution (1.5–7 nm). Compared with the bulk Co3O4, the porous nanorods have a higher CTL intensity of CO oxidation, and a higher activity of CH4 combustion especially at a higher gas hourly space velocity (GHSV), which has been ascribed to its porous structure and larger surface area.

The highly porous Co3O4 nanorods show a higher catalluminescence (CTL) intensity and activity of CO oxidation, and a significantly higher activity for CH4 combustion especially at a high gas hourly space velocity, which has been ascribed to the highly porous structure.Figure optionsDownload as PowerPoint slideHighlights
► We adopt a simple hydrothermal method to synthesize Co3O4 nanorods organized by nanoparticles.
► The sample shows the excellent catalluminescence (CTL) intensity and reactivity of CO oxidation.
► The CTL is a fast mode to screen catalysts from thousands of materials.
► A high activity for CH4 combustion is obtained especially at a high space velocity. The highly porous structure facilitates the mass transfer particularly at high space velocity.