One-Pot Facile Fabrication of Multiple Nickel Nanoparticles Confined in Microporous Silica Giving a Multiple-Cores@Shell Structure as a Highly Efficient Catalyst for Methane Dry Reforming

Methane dry reforming (MDR) is a very important reaction, which can efficiently use two kinds of greenhouse gases (CO2 and CH4) to prepare synthesis gas or produce green hydrogen energy. What inhibits the industrialization of MDR is the sintering of active Ni nanoparticles and severe carbon deposition for Ni-based catalysts. To resolve these problems, a novel structured catalyst with multiple ultra-small Ni nanoparticles (4.3 nm) as the core and microporous silica as the shell was rationally fabricated by a facial one-pot reverse micelle method and applied for MDR. The multiple-cores@shell (M-Ni@SiO2) catalyst displays superior carbon resistance and long-term du-rability with the methane and carbon dioxide conversion close to thermodynamic equilibrium and a H-2 to CO molar ratio near 1, whereas the commercial catalyst, Ni/Al2O3, and Ni directly supported on silica spheres (Ni/SiO2) show low stability and notable carbon deposition. The ultra-small Ni particle size and confinement effect of the porous silica shell are believed to be the determining factors for the outstanding performance of the multiple-cores@shell catalyst. The novel multiple-cores@shell structure catalyst could be potentially used for industrial applications of MDR.