Oxidation of the secondary O–H bond of glycerol to dihydroxyacetone is an important reaction in the production of high-value-added chemicals. The heterogeneous catalytic oxidation route using supported Au as a catalyst in this crucial reaction has attracted considerable attention. However, targeted activation of the secondary O–H bond and satisfactory catalytic efficacy remain considerable challenges. This work reports layered double hydroxide (LDH) supported Au catalysts for the targeted activation of the secondary O–H bond and provides deep insights into the active sites and the roles of the LDH support in glycerol selective oxidation. By virtue of the tailorable chemical composition of the LDH brucite-like layer, Zn2Fe-, Co2Al-, Zn2Al-, Zn2Ga-, and Mg2Al-LDHs, displaying varied surface basic densities and hydroxyl vacancies (VOH), were applied as supports for Au nanoparticles in this work. A glycerol conversion of 72.9 ± 0.2% and a dihydroxyacetone selectivity of 63.8 ± 0.2% were achieved on ZnGa-LDH-supported Au. In addition to Au0, surface Au n+ (Au+ and Au3+) species are abundant in the interfacial MII–O–Au n+ linkages. Detailed investigations verify the cooperation between the surface basic sites on the LDH support for the activation of the secondary O–H bonds and the interfacial MII–O–Au+ sites for the activation of the secondary C–H bonds. Significantly, on Zn-containing LDHs, an additional synergy exists between the surface VOH sites and the interfacial ZnII–O–Au3+ species to further promote catalytic activity.

The selective oxidation of glycerol to glyceric acid, an important value-added reaction from polyols, is a typical cascade catalytic process. It is still of great challenge to simultaneously achieve high glycerol activity and glyceric acid selectivity, suffering from either deep oxidation and C-C cleavage or poor oxidation efficiency from glyceraldehyde to glyceric acid. Herein, this work, inspired by nature, proposes a cascade synergistic catalysis strategy by atomic and low-coordinated cluster Pt on well-defined Cu-CuZrOx, which involves enhanced C-H activation on atomic Pt1 and O-H activation on cluster Ptn in the oxidation of glycerol to glyceraldehyde, and cluster Ptn for C=O activation followed by O-H insertion and atomic Pt1 for C-H activation in the tandem oxidation of glyceraldehyde to glyceric acid. The enhanced C-H activation in the cascade process by atomic Pt1 is revealed to be essential for the high glycerol activity (90.0±0.1%) and the glyceric acid selectivity (80.2±0.2%).

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Enamel glaze was added with glass powders of different sizes and masses and fired into enamel coatings on the surface of low-carbon steel. Acid resistance of the enamel coatings in H2SO4 solution was analyzed by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and mass loss of acid corrosion. As was discovered in research, the acid corrosion quantity in the enamel coatings decreased with the decrease in the particle size of the glass powder when the particle size of the additive glass powder reduced from 100[Formula: see text][Formula: see text]m to 1–2[Formula: see text][Formula: see text]m and heated the prepared enamel coatings in the H2SO4 solution until 80[Formula: see text]C and kept for 48[Formula: see text]h. When the additive amount of the glass powder increased from 5% to 20%, the surface of the enamel coating was smooth and flat with good glossiness and without defects like obvious bubbles and cracks, and the acid corrosion quantity decreased with increase in the additive amount of glass powder, which decreased from 43.24[Formula: see text]mg/cm[Formula: see text]d to 4.28[Formula: see text]mg/cm2.d, satisfying the acid-proof performance requirements of industrial enamel coatings.