Dry Reforming of Methane over Ni-Fe-Al Catalysts Prepared by Solution Combustion Synthesis

Dry reforming ofmethane (DRM) is a promising method to utilizetwo greenhouse gases, such as CH4 and CO2, toproduce synthesis gas. In the current work, both monometallic Ni andbimetallic Ni-Fe catalysts with different Fe/Ni molar ratios,synthesized by solution combustion synthesis (SCS) in DRM, were investigatedusing a feed ratio of CH4/CO2/Ar of 1:1:1 at600-900 & DEG;C. The catalysts were characterized by severalphysicochemical techniques such as X-ray diffraction (XRD), scanningelectron microscopy energy-dispersive X-ray (SEM-EDX) spectroscopy,transmission electron microscopy (TEM), CHNS, N-2 physisorption,H-2-TPR, O-2-TPO, NH3-TPD, and thermogravimetricanalysis (TGA). One of the highest hydrogen yields of 81% was obtainedat 93% conversion of CH4 and 94% conversion of CO2 for the bimetallic 15Ni-5Fe-30Al catalyst, which contained,according to XRD, NiAl2O4 spinel and metallicNi phases. The spinel phase was decomposed during the reaction, whilethe Ni3Fe alloy was formed. Catalysts with a higher Fe/Niratio exhibited lower conversion and contained an inactive FeAl2O4 spinel. Rather stable yields of CO and H-2 were obtained in an experiment with 20 h time-on-stream.