Mechanistic in situ insights into the formation, structural and catalytic aspects of the La2NiO4 intermediate phase in the dry reforming of methane over Ni-based perovskite catalysts

• La 2 NiO 4 exhibits remarkable kinetic metastability in the DRM mixture up to 800 °C. Decomposition of yields mainly a Ni/La O 3 composite. Reaction-formed hydrogen aids decomposition at lower temperatures. Considerable coking and encapsulation exsolved Ni revealed by situ XRD. We focus on stability bulk/surface structural properties Ruddlesden-Popper phase their consequences for dry reforming methane (DRM) activity. Fuelled appearance as crucial intermediate during highly DRM-active LaNiO perovskite structures, we show that can be equally decomposed into offering CO capture release necessary activity, albeit much higher temperatures compared . also leads an active phase. In X-ray diffraction operation reveals considerable Ni, yielding smaller crystallites , where is virtually absent. Generalizing importance phases, La-based structures several obstacles due high both parent occurrence parasitic structures.