To ensure high activity and to maintain stable performance over a long period of time by incorporating an alkali metallic element into an oxide contg. silicon and a specified element when an oxide catalyst contg. silicon and the elements is produced.
An oxide contg. silicon and an element (X) is prepd. and an alkali metallic element (M) is incorporated into the oxide to produce the objective oxide catalyst represented by the formula [where X is at least one element selected from among IIIb, IVb, Vb, VIb, IIIa, IVa other than Si and Va elements of the Periodic Table, lanthanoids and actinoids, (a) to (d) are the numbers of the elements, (a) is 1, (b) is 1-500, (c) is 0.01-1 and (d) depends on (a) to (c) and the bonding state of the constituent elements]. The change of the physical structure of the catalyst during reaction is suppressed and the catalyst has high activity and can maintain stable performance over a long period of time.
MORI TOKUHARU
SAITO NOBORU