| 摘要 |
The invention relates to a process for preparing lactams by cyclizing hydrolysis of amino nitriles with water in the gas phase on catalysts which comprise oxides or mixed oxides of the metals of groups 3, 4, 5, 13 and/or 14 of the Periodic Table, where appropriate in addition a metal oxide of groups 6, 7, 8, 9 and/or 10, and further comprise a phosphate, carbonate, silicate, arsenite, arsenate, antimonite, antimonate and/or nitrate of said metals and/or, if metal oxides of groups 6, 7, 8, 9 or 10 are present, a sulfate of the abovementioned metals. |
