Yolk–Satellite–Shell Structured Ni–Yolk@Ni@SiO 2 Nanocomposite: Superb Catalyst toward Methane CO 2 Reforming Reaction

The CO 2 (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@SiO 2 nanocomposite for the DRM reaction by varying the shell thickness of Ni@SiO 2 core shell nanoparticles. The formation of Ni–yolk@Ni@SiO 2 is proved to be shell thickness dependent. Compared with Ni@SiO 2, Ni–yolk@Ni@SiO 2 with 11.2 nm silica shell thickness shows stable and near equilibrium conversion for CH 4 and CO 2 for 90 h at 800 °C with negligible carbon deposition. The dual effects of formation of small satellite Ni particles due to strong Ni–SiO 2 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.