Dialkyl carbonates can be prepared by reaction of carbon monoxide with alkyl nitrites in a continuous gas-phase reaction in the presence of a heterogeneous catalyst which is composed of a palladium compound of the type Pd(S-L)2, M12Pd(S-L)4 or M2Pd(S-L)4 which has been applied to a suitable support material, L being a strongly electron-withdrawing group, M standing for an alkali metal and M2 for an alkaline earth metal.
