Methane dry reforming with CO2 is greatly affected by the presence of various form of surface carbon (carbides, graphite, carbon nanotubes (CNT), etc). To characterize them two methods have been chosen: (i) temperature programmed oxidation (TPO) and (ii) transmission electron microscopy (TEM). Ni based mono and bimetallic catalysts were prepared by sol-gel and impregnation method. On sol/gel CeZrNi(s/g) and impregnated Ni/CeZr (imp.) catalysts the Tmax in TPO appeared at 400°C and at 600°C, respectively, which shows different carbon structures. Simultaneously, TEM image pointed out the extensive CNT formation on the impregnated Ni catalyst along with an increase in Ni particle size while for the sol/gel sample the Ni nanoparticles are stabilized. On bimetallic CeZrNiCo(s/g) and CeZrNiRh(s/g) catalysts at least two kinds of surface carbon species coexist. Carbidic (CoCx or NiCx) species are first and after the changing of catalyst structure the CNT and graphitic species become prevailing.
ASJC Scopus subject areas
- Chemical Engineering(all)