Multiscale distribution of Ni in La-promoted NiAl2O4-derived catalysts supported on ceramic foams for intensified dry reforming of methane

Dry reforming of methane (DRM) is an attractive route for biogas valorisation through the simultaneous conversion of CH 4 and CO 2 into syngas. In this work, La-promoted Ni catalysts derived from NiAl 2 O 4 precursors were deposited onto α-Al 2 O 3 -based open-cell ceramic foams by solution combustion synthesis (SCS). Beyond combining known components such as NiAl 2 O 4 -derived Ni, La promotion and structured supports, this study shows that SCS on replica-derived foams induces capillary-driven infiltration of the precursor phase into the intrawall macroporosity of the foam struts. As a result, the catalytic phase was not restricted to an external coating but displayed a multiscale Ni distribution, comprising an accessible external Ni-rich layer and a less accessible internal Ni fraction embedded within the foam-wall porosity. After reduction, well-dispersed metallic Ni nanoparticles of 10–12 nm were obtained. La promotion mainly enhanced basicity and reducibility, while exerting only a modest effect on Ni particle size. Catalytic tests at 700 °C and high space velocity (96,000 h −1 ) showed improved activity and stability for the 6La catalyst, with stable operation over 200 h and very low carbon deposition. These results demonstrate that controlling active-phase accessibility within hierarchical foam architectures is critical for designing robust structured catalysts for intensified DRM.