Catalytic Activity Of MgO Research Articles

An efficient and economical process for lignin depolymerization in biomass-derived solvent tetrahydrofuran

The depolymerization of renewable lignin for phenolic monomer, a versatile biochemical and precursor for biofuel, has attracted increasing attention. Here, an efficient base-catalyzed depolymerization process for this natural aromatic polymer is presented with cheap industrial solid alkali MgO and biomass-derived solvent tetrahydrofuran (THF). Results showed that more than 13.2% of phenolic monomers were obtained under 250°C for 15 min, because of the excellent lignin dissolution of THF and its promotion effect on the catalytic activity of MgO. Furthermore, comparison characterization on the raw material, products and residual solid using elemental analysis, FT-IR, TG-DSC, Py-GC-MS and chemo-physical absorption and desorption demonstrated that this base-catalyzed process can inhibit char formation significantly. Whereas, the fact that thermal repolymerization of oligomer on the pore and surface of catalyst resulting in the declination of the catalytic performance is responsible for the residue formation.

Efficient Preparation and Catalytic Activity of MgO(111) Nanosheets.

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Efficient Preparation and Catalytic Activity of MgO(111) Nanosheets

Preferential growth of MgO(111) nanosheets with a thickness typically between 3 and 5 nm (see TEM image) has been achieved by a simple, efficient, and inexpensive wet chemical route. The MgO(111) nanosheets have been shown to have ultrahigh activity for the Claisen–Schmidt condensation of benzaldehyde and acetophenone.

Efficient Preparation and Catalytic Activity of MgO(111) Nanosheets

Efficient Preparation and Catalytic Activity of MgO(111) Nanosheets

Catalytic properties of magnesium oxides doped with sodium compounds

The physicochemical properties and catalytic activity of MgO doped with sodium compounds that are readily decomposed into sodium or sodium oxides have been examined. By calcination of the MgO doped with such sodium compounds as NaBH4, NaNH2 and NaNO3 at 500 or 700 °C in a flowing inactive gas the basic strength of the MgO increased and the concentration of the basic sites attained a maximum at a loading of 1–3 wt % of sodium. The surface area of the MgO was decreased by the doping of sodium, especially when NaNO3 was the dopant. The cause of the decrease in surface area was ascribable to the sintering effect by sodium on MgO owing to compound formation between MgO and sodium or its compounds. On the other hand, the concentration of one-electron donor centres was a minimum at a loading of ca. 2 wt % of sodium, which was inferred as the cause of both the adsorption of sodium on the centres and the migration of sodium on the MgO surface.The dehydrogenation of cumene proceeds on the basic sites and its activity could be correlated with basic sites with pKa > 15.0.

The Catalytic Activity of MgO, ZnO and their Solid Solutions for the Decomposition of N2O

The Catalytic Activity of MgO, ZnO and their Solid Solutions for the Decomposition of N₂O