Methane Reforming Processes: Advances on Mono- and Bimetallic Ni-Based Catalysts Supported on Mg-Al Mixed Oxides

Ni-based catalysts supported on Mg-Al mixed oxides (Mg(Al)O) have been intensively investigated as catalysts for CH4 reforming processes (i.e., steam reforming (SMR) and dry reforming (DRM)), which are pivotal actors in the expanding H-2 economy. In this review, we provide for the first time an in-depth analysis of homo- and bimetallic Ni-based catalysts supported on Mg(Al)O supports reported to date in the literature and used for SMR and DRM processes. Particular attention is devoted to the role of the synthesis protocols on the structural and morphological properties of the final catalytic materials, which are directly related to their catalytic performance. It turns out that the addition of a small amount of a second metal to Ni (bimetallic catalysts), in some cases, is the most practicable way to improve the catalyst durability. In addition, besides more conventional approaches (i.e., impregnation and co-precipitation), other innovative synthesis methods (e.g., sol-gel, atomic layer deposition, redox reactions) and pretreatments (e.g., plasma-based treatments) have shown relevant improvements in identifying and controlling the interaction among the constituents most useful to improve the overall H-2 productivity.