Abstract: The present invention relates to a process for the preparation of chlorine by gas phase oxidation using a supported catalyst based on ruthenium, characterised in that the catalyst support has a plurality of pores having a pore diameter>50 nm and carries nanoparticles containing ruthenium and/or ruthenium compounds as catalytically active components.

Abstract: The present invention relates to a process for continuously preparing diaryl carbonates from dialkyl carbonates and at least one monohydroxyl compound in the presence of catalysts, and to the use thereof for preparation of polycarbonates. The alkylene glycol obtained in the preparation of the dialkyl carbonate used is recycled by oxidative carbonylation with carbon monoxide in the presence of a catalyst to give the cyclic alkylene carbonate which is in turn converted to the dialkyl carbonate. More particularly, the process utilizes the alkylene glycol obtained for the diphenyl carbonate preparation process (DPC process).