Yolk-Satellite-Shell Structured Ni-Yolk@Ni@SiO2 Nanocomposite: Superb Catalyst toward Methane CO2 Reforming Reaction

The CO2 (dry) reforming of methane (DRM) reaction is an environmentally benign process to convert two major greenhouse gases into synthesis gas for chemical and fuel production. A great challenge for this process involves developing catalysts with high carbon resistance abilities. Herein we synthesize, for the first time, a yolk satellite shell structured Ni-yolk@Ni@SiO2 nanocomposite for the DRM reaction by varying the shell thickness of Ni@SiO2 core shell nanoparticles. The formation of Ni-yolk@Ni@SiO2 is proved to be shell thickness dependent. Compared with Ni@SiO2, Ni-yolk@Ni@SiO2 with 11.2 rim silica shell thickness shows stable and near equilibrium conversion for CH4 and CO2 for 90 h at 800 C with negligible carbon deposition. The dual effects of formation of small satellite Ni particles due to strong Ni-SiO4 interactions and yolk shell structures contribute to its high activity and stability. These findings shed light on the design of other metal yolk silica shell nanocomposites to be utilized in renewable energy transfer processes such as DRM reactions driven by solar energy.