Analysis of heat and mass transfer limitations for the combustion of methane emissions on PdO/Co3O4 coated on ceramic open cell foams

Coated ceramic open cells foams (OCFs) with catalysts offer an attractive alternative to packed bed reactors for process intensification. Here, the effect of 3 wt.% PdO on Co3O4 coated on three different OCF (alumina, silicon carbide and zirconia) was investigated toward the reaction of CH4 combustion in lean conditions. The OCFs were characterized by Raman spectroscopy and FESEM analysis. The operating regime of each OCF catalyst was investigated using a series of mass transfer resistances assuming pseudo first order reaction (large excess of oxygen). The thermal conductivity of OCF plays an important role on the overall performance of the combustion reaction in terms of heat and mass transfer. The best OCF structured catalyst was tested up to 250 hours of time-on-stream, demonstrating good stability. PdO dispersion over the structured catalyst at the fresh and aged status was assessed by STEM analysis.