Mn-substituted Ca–La–hexaaluminate nanoparticles for catalytic combustion of methane

Mn-substituted Ca–La–hexaaluminate rod-like nanoparticles (Ca1−xLaxMnAl11O19−α) with high surface area ranging from 47 to 80m2/g for catalytic combustion of methane have been prepared using alumina sol as the (NH4)2CO3 coprecipitation precursor and a supercritical drying (SCD) method. Ca substitution gave rise to the maximum combustion activity (T10%=459°C) at x=0 owing to the highest surface area. Meanwhile, Ca substitution affects the oxygen sorption property and the oxidation state of Mn ions in the hexaaluminate lattice. Ca0.6La0.4MnAl11O19−α catalyst with high catalytic activities was obtained owing to the excellent performance of activating oxygen.