Methane steam reforming, using nickel/alumina nanocomposite catalyst or nickel/silica-alumina hybrid nanocomposite catalyst

A method of preparing hydrogen from methane-containing gas with a methane conversion of 50% or more, which comprises

• i) a step of providing a first catalyst for methane steam reforming which is prepared by a first step of grinding and mixing a porous alumina support and a nickel-containing compound having a melting point lower than the porous alumina support, and melt-infiltrating the nickel-containing compound into pores of the surface, inside, or both of the porous alumina support in a closed system at a temperature ranging from the melting point of the nickel-containing compound to +5° C. higher than the melting point;
• and a second step of thermally treating the melt-infiltrated composite powder at 400 to 600° C. under reducing gas atmosphere to load nickel particles having the average particle size of 10 nm or less in the porous alumina support;
• or
• a nickel/silica-alumina hybrid catalyst comprising the first catalyst;
• and a yolk-shell shaped second catalyst for methane steam reforming which has a nano- or micro-sized average diameter and includes a hollow shell consisting of porous silica of which inside is accessible to methane;
• and a core consisting of nickel-containing particle located inside the hollow shell;
• ii) a step of applying the first catalyst, or the hybrid catalyst of the first and the second catalysts to a reactor of methane steam reforming;
• iii) a step of reducing to activate the first catalyst, or the hybrid catalyst of the first and the second catalysts;
• and
• iv) a step of feeding methane-containing gas and steam to the reactor of methane steam reforming and carrying out the methane steam reforming by using the activated catalyst for methane steam reforming under the molar ratio of steam/methane (H2O/CH4) of 2 to 4 and the gas hourly space velocity (GHSV) of 50 to 300 NL·gcat−1·h−1 to form hydrogen.