Preparation of aluminum borate whiskers/Co _x Cr _3‐x O ₄ catalysts on channel surface of cordierite honeycomb ceramic for soot catalytic combustion

Abstract The monolith catalysts with the hierarchical microstructure prepared from cordierite honeycomb ceramics by the molten salt reaction and the sol–gel impregnation technology. Aluminum borate whiskers (Al 18 B 4 O 33 ) with the lengths of 10–70 µm and the diameters of 0.1–1.4 µm were grown on the channel surface of cordierite honeycomb ceramics, and cilia‐like microstructure improve the capture ability of soot in exhaust. A series of spinel‐type catalysts Co x Cr 3‐x O 4 have loaded on aluminum borate whiskers using the sol–gel impregnation process, and sample Z/C 1 C 2 ‐0.25 possess the optimal soot catalytic oxidation activity. The study employed various techniques to characterize morphology and phase composition, including scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDS), Brumauer–Emmett–Teller (BET), Fourier transform‐infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), and thermogravimetric and differential thermal analysis (TG‐DTA). The cyclic stability experiments demonstrate that spinel‐type catalysts Z/C 1 C 2 ‐0.25 exhibits excellent structural stability and consistent catalytic performance. This unique microstructure has great potential applications in the field of DPF.