Catalytic Diesel Soot Combustion over FeCo2O4 Monolithic Catalysts with Different Morphologies

Herein, four different morphologies of FeCo2O4 monolithic catalysts were prepared on three-dimensional macroporous (3-DM) Ni foam substrate by a facile hydrothermal route, including nanowire (FeCo-NW), nanobrush (FeCo-NB), nanosheet (FeCo-NS) and porous nanosheet (FeCo-PNS). The contact efficiency between these catalysts and soot particulates was calculated, respectively. The relationships between catalyst morphology and reactivity for soot combustion were analyzed from the perspective of contact efficiency. Among these catalysts, the FeCo-NW displays the highest catalytic activity, with the T10 = 351 ℃, SCO2 = 100%, which is ascribed to its outstanding contact efficiency with soot (60), optimal intrinsic activity (TOF = 1.77 × 10-5s-1), ample surficial active species and exceptional reducibility. In the O2 atmosphere, the catalytic performance of FeCo2O4 catalysts in different temperature ranges is affected by different factors. At low temperatures (T < 380 ℃), the catalytic activity is mainly influenced by contact efficiency. At high temperatures (T = 380-500 ℃), the catalytic activity is comprehensively determined by contact efficiency, redox properties, surface active species and inherent activity.