Additional Calcination Research Articles

Electrophoretically Al-coated wire mesh and its application for catalytic oxidation of 1,2-dichlorobenzene

Wire meshes coated with aluminum powder were developed using an electrophoretic deposition (EPD) method. A porous aluminum layer with a thickness of 100–120 μm can be attached on the wire surface after EPD and thermal treatment. Then additional calcination results in the formation of a thin Al 2O 3 layer in the outer surface of each deposited aluminum particle. The Al–Al 2O 3 coating layer is attached very strongly onto the wire surface due to partial sintering of deposited aluminum particles. A rectangular-shaped honeycomb module that has triangular channels was manufactured by packing alternately a flat sheet and a corrugated sheet of the coated wire mesh to a certain thickness. After a wash-coating of V 2O 5/TiO 2 catalyst powder onto the wire surface of the honeycomb, the wire mesh honeycomb (WMH) catalyst was applied for catalytic oxidation of 1,2-dichlorobenzene ( o-DCB). It shows better catalytic performance than the conventional ceramic honeycomb catalyst due to reduced mass transfer resistance by the existence of holes in the mesh sheet.

Some observations on the thermochemistry of telluric acid

The thermal degradation of H6TeO6 in air has been evaluated critically. Evidence is presented for a decomposition mechanism involving step-wise dehydration of H6TeO6 via non-stoichiometric amorphous solids to polymetatelluric acid and up to a composition corresponding to pyrotelluric acid. No morphological changes were observed during these structural variations and no evidence was found for the formation of allotelluric acid. Further dehydration is accompanied by reduction, which, depending upon the experimental conditions accounts for the considerable variety of results reported previously. Crystalline Te(VI)-Te(IV) oxides are obtained at about 550‡ from which TeO2 is formed by additional calcination at about 620‡.