Comparison of carbon deposition features between Ni/ZrO 2 and Ni/SBA-15 for the dry reforming of methane

Ni-based catalysts supported on ZrO 2 and SBA-15 were employed in dry reforming of methane. The relation between carbon deposition and the deactivation of supported Ni catalysts was studied. Ni/ZrO 2 exhibited superior stability, despite of its high coking rate. Therefore, there was no direct relationship between the coking rate and the deactivation rate. In order to investigate the nature of the coke species during dry reforming of methane, TG-DTA/CO 2 -TPO/TPSR/TEM experiments were conducted on the spent catalysts. Characterization results showed that the formation of CNTS on Ni/ZrO 2 could be responsible for the superior stability. For comparison, the dominant carbon species was encapsulating carbon on Ni/SBA-15, leading to serious deactivation. The main difference between Ni/ZrO 2 and Ni/SBA-15 was the reactivity of carbon species towards carbon dioxide. Coke deposited on Ni/ZrO 2 was oxidized by CO 2 at lower temperature, although carbon species on the two catalysts was similar. Additionally, the results of TPSR illustrated that the surface oxygen species over the zirconia support was involved in the oxidation of coke by CO 2 . The activity of Ni/ZrO 2 was completely restored after the in-situ regeneration with CO 2 , indicating that carbon deposition was greatly removed by CO 2 .