Metallic Support Catalyst For The Reaction Of CO Coupling To Dimethyl Oxalate

In recent years metallic monoliths are becoming increasingly popular due to theirhigh thermal conductivity, lower heat capacities, greater thermal and mechanicalshock resistance, the possibility of thin walls allowing high cell density and lowpressure drop. The key problem of metallic support catalyst is how to preparewell-adhered coating on the metal support. Therefore, the pretreatment of the metalsupport, the preparation of the alumina sol and slurry and the applications of metallicsupport catalysts in the production of dimethyl oxalate (DMO) was studied in thispaper.FeCrAl alloy was chosen as the metallic support. Well-adhered aluminawashcoats on FeCrAl metallic supports were prepared using boehmite sol andalumina slurry. Oxidation time and oxidation temperature all have influence on thesurface morphology of FeCrAl alloy. Dense astatic whisker, which is beneficial to theload of coating, can grow out under900℃for16h. Larger crack or collapse coatingare not conducive to integrity.3.0%of sol coating can guarantee the well-adheredcoating and play an important role as transition layer. The optimum loading of Al2O3is15%.Pd/-Al2O3/FeCrAl honeycomb monolithic catalysts were prepared and appliedin the CO coupling reaction to DMO. The precursors of palladium, prepared by forcedflow drying, can obtain uniform distribution of active phase. The catalyst, whose celldensity is400cpsi, has high geometric surface area and shows better catalyticactivities. It is proved that the alumina layer calcined at1100℃is the optimalsupport for coupling reaction. In addition, the effects of various operation parameterson the coupling reaction were studied, including CO concentration, reaction pressureand space velocity. The Pd/-Al2O3/FeCrAl honeycomb monolithic catalysts used inthe synthesis of DMO from CO in gaseous phase reduced the cost of catalyst greatly,Pd efficiency was much higher than that of a reference pellet catalyst.