Methanation reactivity of carbon deposited directly from CO2 on to the oxygen-deficient magnetite

The methanation reactivity of surface carbon deposited from CO2 on the oxygen-deficient magnetite was studied by the isothermal methanation reaction and the temperature programmed surface reaction (TPSR). In the methanation reaction with H2 gas, in a closed system at 150–200‡C, active carbon, which was not observed by the TPSR measurements, was found. About 20% out of the deposited carbon was in the form of atomic carbon and readily converted into CH4 (5 min) above 150‡C with H2, and about 80% at 300‡C. At 350‡C these atomic carbons were transformed into polymerized carbons, which was less reactive for methanation.

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