A facile approach for the preparation of biomorphic CuO–ZrO2 catalyst for catalytic combustion of methane

A series of novel biomorphic CuO–ZrO2 catalysts were prepared using a cotton bio-template and compared with conventional CuO–ZrO2 catalysts. The physical and chemical properties of the as-obtained catalysts were characterized by techniques including X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), H2-temperature programmed reduction (H2-TPR), and O2-temperature programmed desorption (O2-TPD). The catalytic combustion of methane was chosen as the probe reaction. The results suggested that the bio-template method prepared porous biomorphic CuO–ZrO2 catalysts consist of hollow microtubes. Comparing with conventional CuO–ZrO2 catalysts, biomorphic CuO–ZrO2 catalysts displayed better reducibility and oxygen mobility, stronger metal-oxides synergistic effect, appropriate particle size distribution, and lower activation energy. The crystalline state of zirconia transformed from a single crystallite phase of t-ZrO2 into a complex of m-ZrO2 and t-ZrO2 after introducing the bio-template. With proper CuO content (20 mol%), the biomorphic CuO–ZrO2 catalyst displayed preponderant properties. The compensation of surface lattice oxygen from bulk lattice oxygen was more available at high reaction temperatures.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (171 K)Download as PowerPoint slideHighlights► Biomorphic CuO–ZrO2 catalysts were synthesized by cotton template. ► Superior activity for catalytic combustion of methane. ► A mixture of m-ZrO2 and t-ZrO2 was forced after adding the bio-template. ► Evidences of better oxygen mobility and synergy in the biomorphic samples. ► 20 mol% CuO for the biomorphic catalysts was found as the threshold.