[Zurück]

P. Kheyrollahi Nezhad, M. Bekheet, N. Bonmassar, L. Schlicker, A. Gili, F. Kamutzki, A. Gurlo, A. Doran, Y. Gao, M. Heggen, S. Schwarz, J. Bernardi, A. Niaei, A. Farzi, B. Klötzer, S. Penner:
"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";
Applied Catalysis A: General, 612 (2021), S. 1 - 11.

We focus on the stability and bulk/surface structural properties of the Ruddlesden-Popper phase La2NiO4 and
their consequences for dry reforming of methane (DRM) activity. Fuelled by the appearance as a crucial intermediate
during in situ decomposition of highly DRM-active LaNiO3 perovskite structures, we show that La2NiO4
can be equally in situ decomposed into a Ni/La2O3 phase offering CO2 capture and release necessary for DRM
activity, albeit at much higher temperatures compared to LaNiO3. Decomposition in hydrogen also leads to an
active Ni/La2O3 phase. In situ X-ray diffraction during DRM operation reveals considerable coking and encapsulation
of exsolved Ni, yielding much smaller Ni crystallites compared to on LaNiO3, where coking is virtually
absent. Generalizing the importance of intermediate Ruddlesden-Popper phases, the in situ decomposition of Labased
perovskite structures yields several obstacles due to the high stability of both the parent perovskite and the
Ruddlesden-Popper structures and the occurrence of parasitic structures.

CO2-activation B-site exsolution Polymorphism In situ decomposition

http://dx.doi.org/10.1016/j.apcata.2020.117984