| 摘要 |
A dehydration catalyst (particularly useful for vicinal diols such as methyl-2,3-butane-diol,an isopreneprecursor) formed of calcium pyrophosphate, and possibly at least one pyrophosphate, whether mixed or not, of at least one metal from the group consisting of lithium, sodium, strontium, and barium, and/or at least one neutral orthophosphate, whether mixed or not, of at least one metal selected from the group consisting of lithium, sodium, strontium, barium, and calcium Also processes for making and utilizing such catalysts; for example, a process including the steps of: (a) Mixing calcium pyrophosphate and/or dicalcium orthophosphate and at least one pyrophosphato, whether mixed or not, of at least one metal from the group consisting of lithium, sodium, strontium and barium; and/or at least one acid orthophosphate, whether mixed or not, of at least one metal from the group consisting of lithium, sodium, strontium and barium, in the form of dry and/or moist powders to which water may be added to give a paste. (b) Drying at a temperature comprised between 70 and 120.degree.C. (c) Calcining of the catalyst at a temperature comprised between 300 and 600.degree.C, and preferably between 350 and 500.degree.C. |
