Studies On Coke-resistant Properties Of Runi Catalysts For Methane Reforming With CO₂

The greenhouse effect caused by carbon dioxide makes a great contribution to the change of global climate, such as, increasing global temperature, melting glacial and raising sea level, which threats to human survive. So lots of researchers have focused on the utilization of carbon dioxide. Dry reforming combines carbon dioxide and methane, which generates the most valuable basic raw materials for chemical industry. Dry reforming can be combined with other reforming reactions, and the H2/CO ratio can be adjusted to satisfy the diversity of the downstream products.There are two kinds catalysts, including transition metal catalysts and noble metal catalysts. Even though noble metal catalysts have high activity, stability, and excellent resistance to coke resistant, noble metal catalysts are too expensive to be employed by large scale in industry. Whereas nickel catalysts also have good activity, it is prone to deactivation caused by coke deposition.In this paper, we modified nickel-based catalysts through adding noble metal additive and prepared catalysts with alkaline MgO for carrier, Ru for additive and Ni for active component to improve the stability of catalytic reaction. And we also studied on the kinetics properties of reforming reaction over catalysts prepared in this paper.RuxNi0.07-xMg0.93O catalysts, whose surfaces were mainly covered by (111) facets, were prepared by methanol-solvent-thermal method. We adopted XRD, IR, SEM, TEM, etc characterizations methods to analyze the characters of intermediates, oxides after calcined and catalysts after hydrogen reduction. From those data we found that in spite of new phase separation after adding Ru additive, Ru still interacted with Ni to reduce Ni particle size and has an positive effect on coke-resistant.Catalytic performance and stability of RuxNi0.07-xMg0.93O catalysts had been evaluated under rigorous conditions for 100 h. And the spent catalysts were characterized by XRD、TEM、 XPS、TG etc. means and the results show that adding Ru additive can induce the generation of active carbon. Apart from that, the results about kinetic test show that the activation energy of catalyst gradually increase to a certain value along with the increasing of Ru content.Adding noble metal ruthenium additive not only improve the stability of catalytic performance, but also improve the coke-resistant ability of catalysts by inducing the generation of active carbon.