Catalytic dry-reforming on Ni–zeolite supported catalyst

In the present work, the catalytic behaviour in the dry reforming of methane on Ni-based Silicalite-1 type catalyst was studied. The Silicalite-1 support has been synthesized in order to check the role of the silanol groups on the overall catalyst performance: methane and carbon dioxide conversion, hydrogen/carbon monoxide ratio and coke deposition. The population of defect groups on the Silicalite-1 surface was modified by aging of the gel, thermal treatment, ionic exchange and silylation procedure. Among these treatments, the silylation of the support surface leads to the formation of smaller and more reducible Ni-oxide species that not only improve the CH4 and CO2 conversion but also reduce the deactivation of the catalyst due to coke deposition and the obtained H2/CO value is 1.04.

The catalytic behavior in the dry reforming of methane on Ni-based Silicalite-1 type catalyst was studied. Different post-synthesis treatments have been applied to the Silicalite-1 supports in order to affect the external surface. High amount of silanol groups on the Silicalite-1 support surface allows to obtain, during the metal activation, high amount of nickel silicate species. This high amount preserves the catalyst from high coke deposition but the H2/CO ratio is higher than unity. Substituting the OH groups of the support with larger organo-silane groups, before the nickel impregnation, the formation of smaller and more reducible Ni-oxide species occurs (below figure). This kind of catalytic sites improves the overall catalytic performance of the Ni-based catalyst in the dry reforming of methane: higher CH4 and CO2 conversion, H2/CO ratio nearer to unity and lower carbon deposition.Figure optionsDownload high-quality image (158 K)Download as PowerPoint slideHighlights
► We observed the influence of silanol groups on catalyst activity in the reforming.
► Post-synthesis treatments have been applied to the support.
► Ni supported catalyst on silylated Silicalite-1 surface has been tested.
► High CH4 and CO2 conversion values have been obtained.
► H2/CO ratio near to unity and lower carbon deposition have been obtained.