A study on FeCrAl foam as effective catalyst support under thermal and mechanical stresses

Adhesion properties of washcoated γ-Al2O3 layer on FeCrAl metal foams were investigated. For comparison, planar FeCrAl foil was also investigated. Weight gain after washcoating was 19–20 wt.% for FeCrAl foams without preoxidation. It was much higher than that of planar FeCrAl foils that went through preoxidation. Thermal shock test with 1000 cyclic heating and cooling up to 700 °C showed that long term stability of washcoated γ-Al2O3 layer on FeCrAl foam was also good. Specific surface area of the γ-Al2O3 layer was reduced from 97 to 80 m2/g, but weight loss was very low and close to 0%. We attributed this superior thermal property of FeCrAl foam to minimal interfacial force built up by thermal stress at the interface of γ-Al2O3 layer and FeCrAl foam surface. Mechanical stress tests by ultrasonic in petroleum ether solution also showed very good robustness of washcoated γ-Al2O3 layer on FeCrAl foam against the stress with very low weight loss (less than 1%). Such excellent stabilities against thermal and mechanical stresses indicate that FeCrAl foam is a good candidate for catalyst supports under thermally and mechanically harsh environments.

► We loaded very high amount of alumina washcoat on FeCrAl foam (~ 20 wt.%).
► Adhesion of the washcoat to the foam was good enough to withstand thermal shock test.
► Good adhesion of the washcoat was explained by the negligible interfacial force.
► Mechanical stress test also showed very good adhesion of alumina washcoat to the foam.