Hierarchical meso–macroporous titania-supported CuO nanocatalysts: preparation, characterization and catalytic CO oxidation

Hierarchically mesoporous–macroporous titanium dioxide (MMTD) was synthesized by the hydrolysis of tetrabutyl titanate in the absence of surfactant and autoclaving at 60 °C, which exhibits a porous hierarchy of wormhole-like mesostructure in the framework of macrochannels. Different contents of CuO nanoparticles were supported on the MMTD by a deposition–precipitation (DP) method, retaining the high surface areas and hierarchical porosity. The prepared MMTD support and the resulting CuO/MMTD nanocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption analysis, temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS) techniques. Their catalytic behavior for low-temperature CO oxidation was studied by using a microreactor–GC system, and the CuO/MMTD catalyst with 8 wt% CuO content and calcined at 400 °C was found to have the highest catalytic activity. The catalytic activity depended on the CuO loading amount, the precalcination temperature, the meso–macroporous framework, the surface area, and the particle size of the CuO/MMTD catalysts.