Atmosphere-Induced Strategy of Mo-Promoted Ni Encapsulated in Silicalite-1 for Dry Reforming of Methane

Dry reforming of methane (DRM) offers a promising route to convert greenhouse gases into syngas, although fabricating Ni-based catalysts with long-term stability during reaction conditions remains challenging. Unlike the conventional H 2 pretreatment typically required for activating Ni-based catalysts prior to DRM, we herein reported a one-pot hydrothermal encapsulation strategy to directly synthesize Ni-Mo bimetallic catalysts confined within silicalite-1 (Ni x Mo@S-1) under CH 4 /CO 2 atmosphere for catalyst activation. In contrast to the conventional impregnation Ni 5 Mo/S-1 catalyst, this structural encapsulation approach effectively improved nickel dispersion and enhanced catalytic performance. XRD and TEM revealed that the encapsulated Ni 5 Mo@S-1 exhibited ultra-small nanoparticle size (∼2.3 nm) and Mo promoted high dispersion of Ni nanoparticles. Furthermore, XPS and XANES confirmed that Ni 5 Mo@S-1 facilitated the direct reduction of NiO to metallic Ni under CH 4 /CO 2 atmosphere, thereby inducing active Ni 0 sites and Ni-O-Si bond formation with reinforced metal-support interaction. Graphical The CH 4 /CO 2 atmosphere-induced strategy of encapsulation of Ni x Mo@S-1 enhances DRM performance. Pretreatment with different atmosphere revealed the distinct roles of CH 4 /CO 2 in fabricating the confinement structure of Ni 5 Mo@S-1 for DRM. The CH 4 /CO 2 pretreatment atmosphere directly drives the formation of both active Ni 0 and stabilizing Ni─O─Si bonds with the promotion of Mo, remarkably reinforcing metal-support interaction.