Short communicationPreparation of cobalt-copper-aluminum spinel mixed oxides from layered double hydroxides for total oxidation of benzene

- Co-Cu-Al layered double hydroxide was decomposed to give (Co, Cu)(Co, Al)2O4 spinel.
- Cu2 + cations were incorporated into the spinel structure.
- The Co oxide reducibility was significantly improved by the presence of Cu.
- The incorporation of Cu into Co-Al spinel enhanced the catalytic activity remarkably.

Mixed metal oxides Co5 − xCuxAl (x = 0-0.5) were prepared from Co-Cu-Al layered double hydroxides (LDHs) and tested for benzene total oxidation. By calcination, Co-Cu-Al LDHs were mainly transformed to (Co, Cu)(Co, Al)2O4 spinels, where both Cu2 + and Al3 + cations were incorporated into the spinel structure. The incorporation of Cu significantly improved the Co oxide reducibility and remarkably enhanced the light-off activity as well as the total conversion activity, indicative a strong interaction between Cu2 + and Co3 + active sites. The optimum Co4.75Cu0.25Al spinel mixed oxide was comparable with a 0.3%Pd/γ-Al2O3 catalyst, highlighting the promoting effect of structural modification with Cu.

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