| 摘要 |
<p>A supported catalyst, containing vanadium pentoxide, titanium dioxide, phosphorus, rubidium and/or cesium, with or without zirconium dioxide, in which the catalytic material contains from 1 to 40% by weight of V2O5, from 60 to 99% by weight of TiO2 and any optionally added IrO2 and, based on the total amount of ?iO2, ?rO2 and V2O5, up to 2% by weight of phosphorus and up to 1.5% by weight of rubidium and/or cesium, and which comprises two layers, of which the inner layer contains more than 0.2 and up to 2% by weight of phosphorus, but no rubidium and/or cesium, and the outer layer contains from 0 to 0.2% by weight of phosphorus and from 0.02 to 1.5% by weight of rubidium and/or cesium, the outer layer accounting for from 10 to 90% by weight of the total catalytic material.</p> |
