3 mm and are prepared by tabletting they have the following composition ______________________________________ c sub 1 c sub 2______________________________________nio 21 6 12 al sub 2 o sub 3 67 10 88 cao 11 80 sio sub 2 0 21 na sub 2 o k sub 2 o 0 39 ______________________________________ the results are tabulated in table 2 it is seen that even with lower nickel contents the catalysts of this invention have for the most part a higher activity than catalysts c furthermore the deactivation rate of the catalysts of this invention is slower as can be inferred from the methane content at same temperature after a 24h working period and after several successive steaming steps table 2______________________________________ residual methane at various temperaturescatalyst conditions 650 760 870______________________________________a sub 3 at 10 2 of ni 2 18 0 75 after 24 h 2 90 1 42 after steaming 12h 2 73 0 7b sub 1 at 9 3 of ni 6 03 1 42 0 26 after 24 h 6 7 1 45 0 31 after steaming 12 h 8 42 2 33 0 32 after steaming 12 h 7 6 1 54 0 25 after steaming 12 h 6 33 2 17 0 15b sub 1 at 6 5 of ni 8 3 11 1 08 after 24 h 9 3 1 1 06 after steaming 12 h 13 3 48 0 75b sub 1 at 3 6 of ni 9 07 2 61 0 69 after 24 h 8 6 2 98 0 99c sub 1 at 21 6 of ni 6 05 1 63 0 70 after 24 h 7 84 2.