Catalytic decomposition of methane over carbon blacks for CO2-free hydrogen production

Catalytic characteristics of carbon blacks for methane decomposition were investigated. The reaction was carried out under atmospheric pressure at 1023–1323 K. Carbon blacks exhibited stable catalytic activity despite of carbon deposition. No trend could be induced between the activity and the surface area of fresh samples. The reaction order was near unity and the activation energies over carbon blacks were significantly lower than those over activated carbons. It was observed that the deposited carbon formed many protrusions on the particles and made the particles bigger and stuck together. In spite of marked changes of the carbon morphology during the reaction, it is noteworthy that the activity of carbon blacks was maintained nearly constant. The nature of active sites was discussed.