Insights into the interface of NiCo2O4 spinel /LaCoO3 perovskite nano-composite for CO and soot oxidation

Abstract

In the quest for the development of thermally stable, highly active and low-cost catalysts for use in catalyzed diesel particulate filter, nano-composites are new areas of research. Therefore, we reported the easy synthesis of spinel NiCo₂O₄/perovskite LaCoO₃ nano-composite, and its individual oxides NiCo₂O₄ and LaCoO₃ for comparison. The detailed insights into the physio-chemical characteristics of formed NiCo₂O₄/ LaCoO₃ nano-composite were done based on various characterization analysis such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR), N₂ physiosorption, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The characterization analysis of NiCo₂O₄/LaCoO₃ revealed the successful formation of a chemical interface possessing strong interfacial interaction, resulting in desirable physicochemical characteristics such as small crystallite size, abundant mesoporosity, high specific surface area and activation of surface lattice oxygen. Owing to the desirable characteristics, the activity results over NiCo₂O₄/LaCoO₃ nano-composite showed the excellent CO oxidation performance and high soot oxidation activity, recyclability and thermal stability. This work mainly attempts to emphasize the effectiveness of the facile, inexpensive and conventionally used precipitation method for the successful formation of highly efficient nano-composites.

Keywords: CO oxidation; Chemical interface; LaCoO(3); NiCo(2)O(4); Soot oxidation; Spinel/perovskite.