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A series of Ni-containing hydrotalcites with different basicities have been prepared by introducing different Mg 2+ contents, and characterized by XRD, SEM, TG-DTG, ICP, FTIR, Hammett analysis, DR UV-Vis, XPS, et al. The effects of basicity on the catalytic performance in the selective aerobic oxidation of alcohols and the mechanism have been studied. The results showed that substituting Ni 2+ in the structure by Mg 2+ ions significantly increased the surface basicity of the catalysts. The surface basicity of Ni-containing hydrotalcites could accelerate the first acid-base reaction step in the oxidation and improve the catalytic activity. Varied alcohols were tested and discussed in the reaction system to verify the effect, and the results indicated that the activity of α-C-H bond is the key factor for the benzyl alcohol derivatives, while the first base-acid reaction step may be more important for aliphatic alcohols. The comparison results between the hydrotalcites and the calcined samples showed that the type of basic site have significantly influence on the catalytic activity, and only the Brønsted OH basic sites accelerate the oxidation. In addition, a probable mechanism for the reaction was postulated based on catalytic results, Hammett and a series of controlled experiments. The main factors affecting the catalytic oxidation of varied alcohols using molecular oxygen as the ultimate oxidant have been discussed, which may be helpful in designing more efficient catalyst.

The surface Brønsted OH basic site on NiGa hydrotalcites was suggested to be the key active site for the oxidation.

A series of CO32−–CoxFe–LDHs (x = 2, 3, 4 and 5) compounds with different Co/Fe ratios have been prepared, characterized and introduced into the selective oxidation of alcohols by tert-butylhydroperoxide.

Ab ifunctional heterogeneous catalystb ased on the easily produced and economic NiGa layered double hydroxide hasb een developed for the aerobic oxidation/ condensation tandem reactions between aromatic alcohols and active methylene compounds. Good tolerance for varied alcohols and nucleophiles has been observed. Control experiments verified the bifunctional role in the tandem reaction. The protocol could open up new perspectives in the rational design of efficient bifunctional catalytic systems.Ta ndemr eactions have attracted significant attentionb ased on their improved overall process efficiency and reduced production wastes. [1] Designing multifunctional catalysts with spatially isolated multiple active sites is essentialf or progressing multistep reaction cascades. Generally,i ti sm ore easier for heterogeneousc atalysts than for homogeneous ones to incorporate differentc atalytic sites in one system. [2] a,b-Unsaturated aromatic dicyanides are very important intermediates in the design and synthesis of suitable drug molecules.S ome heterogeneous catalysts, such as Pd-nanoparticle-supported Nano-ZSM-5, [3] Pd/LS-AT-OH À catalyst, [4] Pd 0 @UiO-68-AP, [5] porphyrinbased microporous organic polymer Fe-POP-1, [6] and polyoxometalate( POM)-intercalated layered double hydroxides, [7] Pd 1 -Au 1 /LDH [8] have been reported for the synthesiso ft hese compounds through alcohol oxidation/Knoevenagel condensation tandem reactions. Although these materials were efficient for the tandemr eactions, they had some drawbacks, such as requiring ac ostly multistep synthetic route to obtain these catalysts, noble metals, and sometimes oxygen donors such as [a] Dr.

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