Inducing Ni phyllosilicate formation over a carbon fiber support as a catalyst for the CO2 reforming of methane

Silica-coated carbon fibers were prepared via a modified hydrothermal method with three separate catalysts synthesized by changing the sequence of Ni and SiO2 precursor addition to the carbon fiber and the as-prepared catalysts were utilized in the CO2 reforming methane reaction. It is found that the addition order of SiO2 and Ni precursors governed catalyst performance, where the addition of Ni and SiO2 precursors simultaneously (SiO2 Ni@CF) has led to high stability for long-term operation at 700 degrees C. Particularly, CO2 conversion rate over SiO2Ni@CF catalyst was maintained at approximately 85 % after 24 h. The superior performance of SiO2Ni@CF is attributed to the formation of Ni phyllosilicate species. Simultaneous Ni-SiO2 addition facilitated a decrease in the particle size of the active Ni deposits via a confinement effect. The confinement effect constrained the reduced Ni particles to a lamellar phyllosilicate structure which introduced greater activity and an enhanced resistance to metal sintering.