Influence of Preparation Method for CuAl Mixed Oxide Issued from LDH for Total Oxidation of VOC

Abstract Cu 6 Al 2 mixed oxides derived from layered double hydroxide precursors were synthesized by three methods: co‐precipitation, microwave‐assisted, and ultrasound‐assisted methods. The mixed oxides obtained after calcination were studied by several techniques: XRD, N 2 ‐sorption, H 2 ‐TPR, and XPS. The catalytic materials were also tested as catalysts in the reaction of total oxidation of toluene, carbon monoxide, and the mixture of both. The physicochemical studies revealed a modification of the structural characteristics (surface area, morphology) as well as the reducibility of the formed mixed oxides. The solid prepared by microwave‐assisted synthesis was the most active of the three reactions. Furthermore, relationships between the ratio of Cu/Al on the surface, the O adsorbed /O bulk ratio of the CuAl mixed oxides surface, and the T 50 in toluene oxidation in the presence of CO were demonstrated. These relationships suggest a Mars Van Krevelen mechanism for toluene total oxidation in the presence of CO for these three catalysts.