摘要 |
<p>The support material, which is based on silica fillers and clay minerals, contains not more than 4% of Al2O3 and is impregnated with a solution, containing a small amount of sulphuric acid, of vanadyl oxysulphate in which the vanadium is in the + IV oxidation state, and potassium hydrogen sulphate. The support material is cured at below 600 DEG C.</p> |