Manganese Oxides as Promotors for Reforming Processes

Catalytic carbon dioxide reforming of methane (dry reforming methane, DRM) is an excellent alternative route to obtain syngas and has received significant attention in recent years due to its scientific and industrial importance, since it converts two greenhouse gases (methane and carbon dioxide) into valuable synthesis The DRM process is industrially 

Kiylov et aZ. studied the catalytic reaction of methane with carbon dioxide over MnO -containing catalysts for syngas production. The effect of the modification of nickel by different additives, such as copper, chromium, iron and manganese oxides, was evaluated and the best effect was obtained with manganese oxide an increase of manganese content originated an increase of the carbon dioxide conversion and a decrease of coke formation. 

A series of Ni/y-Al203-based catalysts as well as the corresponding catalysts modified by promoters including MnO were prepared by Nandini et al, and their catalytic performance on DRM reaction was studied.The 13.5Ni-2K/ 5Mn0-Al203 catalyst showed lower activity (59.5% methane conversion) than the unmodified nickel catalyst (72.8%) at 973 K (Table 11.2 entiy 5). This marginal decrease in the activity of the manganese-modified nickel catalyst 

Cobalt-based catalysts also attracted researehers attention as an aetive metal for dry reforming of methane. Cobalt-supported catalysts (Co/Zr02) modified with different metal additives were recently studied by Ozkara-Aydinoglu et The addition of manganese to Co/Zr02 improved the metal dispersion properties on the surface and had a stabilising effect on the catal3dic activity (80% of its activity was maintained after 6 h. Table 11.2, entry 9) with the suppression of coke formation nevertheless, this effect was not so pronounced as with other promoters. 

In all these studies manganese showed a positive role in the DRM reaetion and was shown to be a promising element in the future challenge of developing new catalysts with better catalytic activity and stability at lower temperatures avoiding the catalyst deactivation during the DRM reaction. 

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