Precursor Effects on Catalytic Behaviors of Copper–Manganese–Cerium Ternary Oxides Pellets for Low-Temperature CO Oxidation

Abstract

Catalytic oxidation of CO into CO2 using copper–manganese–cerium (Cu–Mn–Ce) ternary oxides pellets represents a promising strategy for CO abatement. In this work, Cu–Mn–Ce ternary oxides catalyst pellets were prepared with different precursors by combining the wet-mixing-kneading and extrusion-spheronization methods. Physicochemical properties of the catalyst pellets were characterized by N2 adsorption–desorption, X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectrometry, transmission electron microscopy, X-ray photoelectron spectroscopy and H2-temperature programmed reduction. CO oxidation performance of the catalyst pellets were investigated in 0.5%CO, 2.0%H2O and balanced air using a fixed-bed reactor. Effects of granulation and precursor on the structure–activity relationships of the catalyst pellets were studied. The granulation process will adversely affect the CO oxidation performance of the as-prepared Cu–Mn–Ce ternary oxides catalysts. The catalyst pellet derived from nitrate precursors (CuMnCe-N) exhibits excellent CO oxidation activity (T50 = 115 °C), good time-on-stream stability (retains about 97% conversion after 85 min of reaction tested) and superior kinetic performance (Ea = 40.32 kJ/mol). The excellent CO oxidation performance is associated with the formed Cu–Ce–O solid solution, enhanced reducibility and dual synergistic effects. Besides, the desired catalyst pellet possesses good mechanical properties with a high mechanical strength of 14.70 MPa and a low attrition rate of 9.46%. The results will provide important guidance for designing efficient catalysts for CO oxidation.