Oxidative coupling of methane on cordierite monoliths coated with Sr/ La2O3 catalysts. Influence of honeycomb structure and catalyst-cordierite chemical interactions on the catalytic behavior

Abstract

When powder Sr/La2O3 catalysts are deposited on the walls of cordierite monoliths, an important increase inboth, methane conversion and C2 yield, takes place. In this work, it is shown that this improved catalytic behavioris due to a combination of physical and chemical factors. This conclusion was drawn after performing asystematic study in which several structured formulations were catalytically evaluated and characterized usingdifferent techniques (EDX, XRD, BET, XPS, LRS), which helped us to rationalize the experimental observations. Itis suggested that the honeycomb structure provides a more homogeneous gaseous flow as compared with thepowder catalyst. This fact results in a better contact between reactant and catalyst surface, which in turn resultsin an increase of the overall reaction rate. Furthermore, it is demonstrated that the catalytic layer enrichmentwith Mg and Si, coming from the cordierite structure, greatly contributes to the improved catalytic behavior.