Patent ID: 7767182

Claim:
A method for producing a nanocarbon and hydrogen comprising: direct decomposing a lower hydrocarbon by using a catalyst comprising a metal carried on a support with subjecting coexistent gas to the lower hydrocarbon to thereby produce the nanocarbon and hydrogen, the coexistent gas comprising low concentration of oxidizing gas, reducing gas or a mixture thereof, wherein the metal content (wt %) of the catalyst is less than that of the support wherein the coexistent gas reacts with excess precursor of nanocarbon produced on the catalyst or an amorphous carbon secondarily produced on the catalyst and removes the nanocarbon and the amorphous carbon from the catalyst, and wherein the coexistent gas comprises hydrogen, carbon dioxide and water, wherein the hydrogen is present in a volume of from 0.05% to 5.0%, the carbon dioxide is present in a volume of from 0.05% to 10%, and the water is present in a volume of from 0.05% to 5.0% or a mixture thereof.