Promotion effects of nickel catalysts of dry reforming with methane

The promotion effects of nickel catalyst of dry reforming with methane were extensively investigated, by means of XRD, SEM, EDX, N-2-adsorption and H- 2-adsorption. XRD characterization indicated that good dispersion of nickel oxide and NW promoter is achieved over gamma -Al2O3 support. Addition of N W promoter effectively retards the formation of NiAl2O4 phase. SEM and EDX analysis exhibited that the addition of rare-earth metal oxide CeCO2 effect ively promotes the Ni metal dispersion on the surface of the catalysts desp ite of undesirable self-dispersion of CeCO2 promoter. Furthermore, the nick el component is gradually dispersed on the surface of the support following the exposure to reaction gas mixture for a period of time. The addition of MgO inhibited the self-dispersion and promotion effect of CeCO2 on Ni disp ersion on the catalysts. H-2 chemisorption revealed that the addition of th e alkaline oxide NW promoter significantly prohibits the metal dispersion o n the catalyst. Inappropriate promoter addition can result in sharp decreas e of the metal dispersion. NI-adsorption indicated that oxide promoter was mostly concentrated on the outer layer of the alumina support while the nic kel metal was generally dispersed in the support pores. Addition of promote rs contributed to more reduction in mesopore volume.