Catalytic oxidation characteristics of CH4-air mixtures over metal foam monoliths

Utilizing catalysts in micro burners is an excellent possible solution to help stabilize fuel combustion. To increase the effective area for catalyst deposition and enhance the catalytic effect, it is proposed in this paper that metal foam is used for preparation of monolithic catalysts. To prove its feasibility, the 4.8 wt.% and 3.2 wt.% Pd/Al2O3/Fe-Ni metal foams (Foam I and II) were prepared through a series of treatment of coating and impregnation. The catalytic performance of both the metal foam based monoliths for methane catalytic oxidation was tested in a catalytic reaction test system. The results showed that Foam I exhibited higher catalytic activity at low reaction temperature. The reaction temperature and flow rate of reactant mixture play an important role in the activity of the catalysts. The results also disclosed that methane concentration has a weak impact on the catalytic activity, which means that the metal foams based monolith catalysts developed in this paper are effective in a wide range of fuel-air ratios.