The Preferential Oxidation Of CO In Hydrogen-rich Stream In A Metal Foam Micro-reactor

Energy is the basic driving force of the development of the world, and supports humanbeing's lifes. With the depletion of fossil fuels, the strategic status of reproducible energy isgetting more important. Hydrogen is supposed to be the most promising energy in the future.Hydrogen production from methanol reforming is one of the most promising approach forproton exchange membrane fuel cells(PEMFC). Due to the strong chemisorption on the anodePt catalyst surface, trace CO will dramatically depress the performance of PEMFC. It is veryessential to clean up CO to an acceptable degree(<100×10-6). Many researches showed thatthe preferential oxidation of CO is the most effective and economic method to remove COdown to 100×10-6level.This paper prepared a kind of micro-reactor which was applied in the removing of COfrom hydrogen-rich gas. Deposit Cu-Ce-Zr-O catalyst onto metal foam nickel throughimpregnation method, the activity of the catalyst, selectivity, stability and adhesivity etc. wereinvestigated as evaluation indexes. Effects of Zr content, praperation and deposit methods,calcination temperature were systematically studied over Cu-Ce-Zr-O catalyst. It was foundthat the optimal components ratio of Zr/Cu(mol ratio) was 1.5, Cu₁Ce₉Zr_1.5O_δcatalystprepared by impregnation method, calcinated at 500℃shows good activity and selectivity.When it was oprerated during 180-240℃, the CO concentration could be reduced below 100×10^-6; and when reaction temperature was between 200-240℃, selectivity was kept at about40 %. XRD results showed: cubic phase CeO₂ is main crystalline phase of Cu-Ce-Zr-Ocatalyst, CuO was highly dispersed as non-crystalline CuO over the surface of CeO₂.Effects of various operation parameters on the preferential oxidation of CO wassystematically studied over Cu₁Ce₉Zr_1.5O_δcatalyst, including reaction temperature, molarratio of O₂ to CO(λ=n_O2/n_CO), CO₂ volume, space velocity, mass of catalyst in a single metalfoam and pre-treatment. The optimal operation conditions are:λ=3, space velocity is 7000 h-1,reaction temperature 200-240℃. Effects of catalyst life and deactivation were investigated.