Direct methane cracking using a mixed conducting ceramic membrane for production of hydrogen and carbon

•Methane thermocatalytic decomposition was studied using a ceramic membrane.•A mixed conducting oxide, Pd-deposited BaCe0.85Y0.15O3 membrane was prepared.•Maximum conversion of methane was measured to be 48.3%.•The periodic CO2 injection minimized the carbon contamination on the membrane.•Carbon nanosheets and nanoparticles were observed after the methane cracking.

The direct cracking of methane can be used to produce COx and NOx-free hydrogen for proton exchange membrane fuel cells. Recent studies have been focused on enhancing the hydrogen production using the direct thermocatalytic decomposition of methane as an attractive alternative to the conventional steam reforming process. We present the results of a systematic study of methane direct decomposition using a mixed conducting oxide, Y-doped BaCeO3, membrane. A dense disk-shaped BaCe0.85Y0.15O3 membrane was successfully prepared and covered with Pd film, as the catalyst for the methane decomposition. For the methane thermocatalytic decomposition, the methane gas was employed as reactant on the membrane side with a pressure of 102 kPa and rate of 70 ml/min at the reaction temperatures of 600, 700, and 800 °C. The hydrogen was selectively transported through the mixed conducting oxide membrane to the outer side. In addition, the carbon, which is a by-product after methane decomposition, showed the morphologies of sphere-shaped nanoparticles and the transparent sheets.