Studies on the transformation of carbon species from CH4 decomposition over a Ni/Al2O3 catalyst

The accumulation of coke mainly from CH4 decomposition on the Ni/Al2O3 cata lyst surface in partial oxidation of CH4 to syngas can lead to the catalyst deactivation. In this paper, we used a sequential pulse technique to inves tigate the reasons of coke formation. Ni-x C from CH4, decomposition is one of the intermediates for partial oxidation of CH4, which can be transforme d into more inert carbon species under the experimental conditions. The gra phitization of carbon from Ni-x C not reacting with surface oxygen in time in partial oxidation of CH4 is the main reason of coke formation.