Self-stabilization of Ni/Al2O3 Catalyst with a NiAl2O4 Isolation Layer in Dry Reforming of Methane

Alumina oxide supported nickel (Ni/Al2O3) catalysts generally suffer from fast deactivation caused by coking and formation of nickel aluminate (NiAl2O4) in dry reforming of methane (DRM). Herein, for the first time, a self-stabilization mechanism of the Ni/Al2O3 catalyst (with 0.1 wt% Ni loading) was revealed and effectively applied for DRM. Namely, the conversion of catalytically active Ni species into catalytically inert NiAl2O4 spinel in DRM over the Ni/gamma-Al2O3 catalyst could be mitigated by repeated reduction-reaction treatments owing to the increasing amount of Ni located on the NiAl2O4 isolation layer rather than the reactive gamma-Al2O3. The self-stabilization could be achieved over Ni/alpha-Al2O3 as well, even with a faster rate, since the NiAl2O4 isolation layer can be directly formed in the first reduction-reaction cycle due to its small surface area and weak metal-support interaction. These observations not only highlight the importance of an isolation layer for protecting the catalyst from deactivation, but also provide a novel and efficient self-stabilization approach for catalytic DRM. [GRAPHICS] .

Automated summary

The study revealed a self-stabilization mechanism of Ni/Al2O3 catalysts in DRM for the first time, which effectively mitigates fast deactivation caused by coking and formation of nickel aluminate. This approach not only highlights the importance of an isolation layer for protecting the catalyst from deactivation, but also provides a novel and efficient self-stabilization method for catalytic DRM.