Catalytic combustion of residual methane on alumina monoliths and open cell foams coated with Pd/Co3O4

The reactivity of a catalytic layer consisting of 3 wt.% of Pd/Co3O4 over an alumina monolith (100 cpsi, diameter 0.9 cm, length 3 cm) and two alumina open cell foams (30 and 45 ppi, diameter 0.9 cm, length 3 cm) in the oxidation of residual methane in lean conditions was investigated. The ceramic structures were coated via solution combustion synthesis (Co3O4) and wetness impregnation (Pd). The catalytic reactivity of the catalysts coated on the structured supports was assessed in a gas mixture containing 0.5 or 1 vol.% of methane at different weight hourly space velocities (WHSV, 30 and 60 NL h–1 gcat–1). Moreover, the prepared structured catalysts were characterized by measuring the pressure drop and determining the volumetric heat transfer coefficients. Both the WHSV and the structure of the support influenced the catalytic activity. In general, open cell foams coated with Pd/Co3O4 show superior catalytic activity than the coated monolith.