Effect of Ca Promoter on the Structure, Performance, and Carbon Deposition of Ni-Al2O3 Catalyst for CO2-CH4 Reforming

Ni-Al 2 O 3 catalyst with different Ca abundance for CO 2 -CH 4 reforming was prepared by the solution combustion method. By some mature characterization methods, such as XRD, H 2 -TPR, EDX mapping, TEM, TPH and TG-DTG technologies, and the reforming experiment, the effect of Ca content on the structure, reforming performance, and carbon deposition of Ni-Al 2 O 3 catalyst was investigated. Results showed that the grain size of active component Ni on the 4 wt % Ca-modified catalyst (Ni-Ca-4) was small (13.67 nm), presenting good dispersion, and that Ni and Ca elements were well distributed on the support, which was more conducive to the CO 2 -CH 4 reforming. Evaluation results showed that activity of Ni-Ca-4 was higher than the others, with CH 4 and CO 2 conversions of 52.0 and 96.7%, respectively, and H 2 /CO ratio close to unit. Carbon deposition proposed that the amount of carbon deposited on the surface of Ni-Ca-4 was lower (18%), and the type of carbon was attributed to amorphous carbon, indicating that 4 wt % Ca-promoted catalyst presented better anticarbon deposition performance.