Catalytic Combustion of Effluents from Methane-based MCFC Device over Cordierite Supported Pd/La-Al_2O_3 Catalyst

摘要

Influence of steam, loading amounts of Pd (viz., 0.7, 2.1, 5.4 wt %) and other process parameters (viz. GHSV and temperature) on methane-based MCFC anode-effluents over Pd-based La_2O_3-Al_2O_3 supported on honeycomb substrate have been investigated. TGA study reveals precise temperature of decomposition of Pd-0 in catalytic combustion at high temperature. An increase in methane conversion at elevated temperature is attributable to decomposition of PdO to Pd active phase. The XRD analysis of spent catalysts suggests that the reflections corresponding to PdO gradually become weaker with increase in the Pd loading. The addition of 4% water in the feed decreases the methane conversion due to the reversible reaction of PdO with water adduct resulting in the formation of inactive Pd(OH)_2 phase. However, the methane conversion remains unaffected and increases monotonously with 100% water concentration in the feed.