(17f) Reverse Micelle Synthesis and Characterization of Nanoparticle Catalysts for Tri Reforming of CO2

Tri reforming is one of the potential processes to convert CO₂ into synthesis gas with desirable CO/H₂ ratio by combining steam reforming, CO₂ reforming, and CH₄ oxidation. Ni supported on different metal oxides such as a-Al₂O₃, TiO₂, MgO, SiO, Cr₂O₃, CaO, or a combination these are potential catalysts for the tri-reforming process.

Reverse micelles were used to improve the nanoparticle size uniformity of Ni and NiSn combinations supported TiO₂ (anatase), which has an abundance of oxygen vacancies within the lattice structure. Two different methods were investigated to optimize the use of reverse micelle: (1) Direct reverse micelle method, where metal cations within the reverse micelle were reduced by NaBH₄ reducing agent, which was diffused into the water droplets, and then supported on TiO₂ and (2) Two reverse micelle system, where both metal cations and the reducing agent form reverse micelle and then react with each other to produce the nanoparticles.

X-ray Diffraction (XRD) was used to characterize the structural properties of Ni (or NiSn)/TiO₂. From XRD, it was estimated that the crystallite size of the supported metal was ~20 nm. Transmission electron microscopy (TEM) was used to confirm the particle size distribution.  Catalyst composition and morphology was determined from SEM-EDX.  Raman and FTIR spectroscopy were utilized to understand the effects of different metal concentrations on the Ti-O band. These findings and possible catalytic reaction mechanisms will be discussed.