Effect of Nd-incorporation and K-modification on catalytic performance of Co3O4 for N2O decomposition

Abstract

Nd-Co3O4 catalysts were prepared by hydrothermal and co-precipitation methods to catalyze the decomposition of N2O. The catalysts prepared by hydrothermal method showed higher activity. Among the hydrothermal Nd-Co3O4 catalysts, the catalyst with Nd/Co molar ratio of 0.01 had higher activity. 0.01Nd-Co3O4 catalyst was then impregnated by K2CO3 solution to prepare K-modified catalyst. The catalysts were characterized by means of X-ray diffraction (XRD), nitrogen physisorption, scanning electrons microscopy (SEM), X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H2-TPR), and oxygen temperature-programmed desorption (O2-TPD). The results show that Nd-Co3O4 and K-modified catalysts exhibit spinel structure. In contrast to bare Nd-Co3O4, the K-modified catalyst with higher activity is due to its weaker strength of Co–O bond and easier desorption of surface oxygen species. In addition, over 90% conversion of N2O can be reached over 0.02K/0.01Nd-Co3O4 at 350°C for 40 h under the co-presence of oxygen and steam in feed gases.