CO_2 Reforming of Methane Over Ni/Carbon Fibers-La_2O_3 Catalyst: Effects of Ultrasound-Assisted Method and La_2O_3 Doping on Catalytic Properties and Activity

摘要

To improve the catalytic efficiency of Ni/carbon fibers (CF), La2O3 was added to CFs to prepare a dual-support catalyst. The catalyst, Ni/CF-La2O3, was synthesized using an ultrasound-assisted method. The catalytic properties were investigated by dry reforming CH4 at temperatures ranging from 700 to 800 degrees C, at a CH4/CO2 feed ratio of 1, at atmospheric pressure, and at a GHSV of 14000 ml/g min. The results show that the activity of the as-prepared catalyst could be enhanced by adding La2O3 and the catalyst prepared by the ultrasound-assisted method showed better catalytic activity than that obtained by impregnation. In addition, all the catalysts used in the experiment were characterized by the BET specific surface area method, atomic absorption spectroscopy, transmission electron microscopy, X-ray diffraction, H-2 temperature-programmed reduction and CO2 temperature-programmed desorption analyses. The results indicate that the as-prepared catalyst exhibited better interactions between the support and metal as well as a higher dispersion of the Ni nanoclusters. Consequently, the Ni/CF-La2O3 catalyst made by the ultrasound-assisted method possesses the greatest catalytic performance, showing potential as a novel alternative in the dry reforming of methane.