TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Device: The first vessel in the reformer further comprises an exhaust zone configured for receiving reacted gases from hot zone. Preferred Components: The metal oxide has formula La1-xA1xB1O3-n (I) and it is disposed on a refractory support (preferably yttria stabilized zirconia).A1=Ca2+ or Sr2+;B1=Co, Mn, or Fe;x=greater than 0 and less than 1;andn=number of oxygen vacancies in the resulting oxide crystal lattice.Preferred Membrane: The membrane (T1) comprises a first section configured for surrounding a less than 900degrees C zone and a second section configured for surrounding a greater than 900degrees C zone in the reactor, where the first section provides a higher oxygen flux than the second section, when an oxygen containing gas is passed over the outer surface. The membrane (T1) or section further comprises a carbon suppression catalyst that converts carbon to at least one carbon oxides to suppress carbon deposition on the inner wall when the reformer (R1) is operated to produce synthesis gas. The membrane (T1) or its section comprises La1-xCaxFeO3-n optionally deposited on a ceramic support, and the reforming catalyst comprises La1-xCaxFeO3-n; or Pt-Rh wire gauze. Preferred Catalyst: The reforming catalyst in hot zone comprises at least one metal selected from platinum (Pt), rhodium (Rh), iridium (Ir), tungsten (W), molybdenum (Mo), cobalt (Co), iron (Fe), and its alloys, or metal oxide (I). The reforming catalyst in hot zone comprises metal oxide, and membrane (T1), or its section, comprises metal oxide (I) that is the same or different than the reforming catalyst. At least one of the reforming catalyst and membrane (T1) comprise at least one metal oxide (I); and optionally refractory support. Preferred Method: The step of passing an oxygen involves effusing sufficient active oxygen from the membrane to the inner wall to maintain the active oxygen level along the inner wall sufficiently high to suppress deposition of carbon on the inner wall. The membrane effuses sufficient active oxygen into the hot zone to maintain a carbon-to-oxygen atomic ratio of 1:1 along the inner wall. The method (M1) involves adding CO2 to the hydrocarbon feed. EXAMPLE - No suitable example is given.