supplied as a gas having at least about 90 weight percent preferably at least about 95 weight percent more preferably at least about 99 weight percent carbon monoxide suitable carbon monoxide containing gases are commercially available from for example air products suitable catalyst include those comprising iron copper nickel cobalt zinc ruthenium rhodium palladium silver cadmium rhenium osmium iridium platinum gold mercury and the like and combinations comprising at least one of the foregoing metals preferred catalysts may comprise copper a highly preferred catalyst comprises copper and chloride ion in a molar ratio of about 0 5 to about 1 5 within this range a molar ratio of at least about 0 8 may be preferred also within this range a molar ratio of up to about 1 2 may be preferred highly preferred catalysts include cuprous chloride cucl and cupric chloride cucl 2 with cuprous chloride being more highly preferred during operation of the process a suitable chloride ion concentration may be maintained by the addition of hydrochloric acid hcl fig1 illustrates a dialkyl carbonate plant 10 having linked reaction section 20 separation section 30 and purification section 40 with reference to fig1 the catalyzed reaction of alkanol oxygen and carbon monoxide may be performed in.