Correlating Properties of the Mn2O3-Na2WO4/SiO2 Catalyst with Statistically Estimated Parameters for the Oxidative Coupling of Methane

Identifying key catalyst parameters that govern catalytic performance is a main challenge for many reactions. The complex and convoluted behavior of the Mn2O3-Na2WO4/SiO2 catalyst for the oxidative coupling of methane (OCM) makes this task even more challenging. Herein, structure-function correlations are obtained using a simplified methodology that involves cross-referencing statistically estimated reaction kinetic parameters with various experimentally measured catalyst and reaction properties. These correlations and conclusions are shown to be consistent with literature data, which was obtained using advanced in situ techniques. Specifically, these correlations highlight the importance of maintaining highly dispersed Mn2O3 particles in a dispersed Na2WO4 melt, under OCM conditions. The promotion of OCM is associated with the efficient interaction of the two phases in the gel-like formation, which apparently promotes the release of the catalytic active species. However, it is also shown that under reaction conditions the molten state of the Na2WO4 promotes the growth of a separate Mn2O3 phase, which enhances CO2 formation over the OCM by reducing the effective level of interaction between the Mn and the W phases. As a whole, this work not only provides new data but also exemplifies a relatively simple and general tool for identifying catalyst descriptors that govern reaction performance.

Automated summary

Identifying key catalyst parameters that govern catalytic performance is a major challenge. Through a simplified methodology, this study highlights the importance of highly dispersed Mn2O3 particles in a dispersed Na2WO4 melt for promoting the oxidative coupling of methane. Experimental results and literature data show consistent correlations, providing insights into the behavior of the catalyst under OCM conditions.