Designing perovskite catalysts for controlled active-site exsolution in the microwave dry reforming of methane

Abstract

The dry reforming of methane (DRM) is a promising process for generating syngas (CO + H2) while consuming CO2, but industrial applications have been limited due to the high temperatures required to prevent coke formation. Microwave-assisted DRM (MW-DRM) is a promising approach to enable high temperature reactions because it can utilize excess renewable electrons to rapidly and selectively heat the catalyst bed without wasting time and energy heating the entire reactor. Here we demonstrate the MW-DRM reaction by modifying lanthanum strontium cobaltite (LSC) to serve as both microwave absorber and catalyst. Catalyst doping studies revealed the addition of oxophilic transition metals prevented over-reduction and stabilized the perovskitic phases under reaction conditions. In situ, synchrotron-based x-ray diffraction revealed the catalyst becomes active once metallic cobalt forms on a retained perovskitic support. The best performing Mn doped LSC catalyst showed 80–90 % single-pass conversions, stable operation for over 10 h, and easy microwave regeneration.