Asymmetric tubular oxygen-permeable ceramic membrane reactor for partial oxidation of methane

Abstract

We report a successful paradigm of implementing the nickel catalyst for partial oxidation of methane (POM) in an oxygen-permeable ceramic membrane reactor (OPCMR). With using air feed, the OPCM (or the cathode of O2 reaction) was completely gastight but presented a desirable oxygen anion flux, which is required by POM in the anodic side. An almost 100% of CH4 conversion with high selectivity of CO and H2 was achieved in the anode, which was initially a composite of YSZ and NiO. It is also found that a mutual diffusion of Ni2+ and Zr4+ ions happens between the YSZ and NiO phases, which affected performance of POM. Besides experimental work, a new activation pathway was proposed to describe cleavage of the first C-H bond of methane. This activation pathway was simulated using the density function-theory and the computed activation energy for breaking up the first C-H bond falls in the experimental measurement range. © 2007 American Chemical Society.