Comparison of nanocrystalline and polycrystalline oxide supports for catalytic oxidation of methane

摘要

Nanocrystaline and polycrystalline ZrO_2, CeO_2 and Mn_3O_4 without and with 5 wtpercent Pd have been tested for methane oxidation. The nanocrystalline catalysts perform better than the polycrystalline catalysts on a weight basis. Nanocrystalline (n)-CeO_2 performs much better than n-ZrO_2, and both perform much better than polycrystalline (p)-CeO_2 and p-ZrO_2. 5 wtpercent Pd/n-ZrO_2 is the best catalyst tested, but 5 wtpercent Pd/n-CeO_2 performs nearly as well. A 20 wtpercent Ag/p-ZrO_2 and a 20 wtpercent Ag/n-ZrO_2 catalyst were also tested. The Ag yields a significant improvement over the bare supports, but not as much so as Pd.