Combined Steam CO2 Reforming of Methane over Ni–Co Bimetallic Catalysts on Granule Type Calcium Aluminate
摘要
Combined steam CO2 reforming of methane (CSCRM) is an excellent method to convert two major greenhouse gases with water into valuable syngas with a suitable H2/CO ratio for valuable chemicals. The scale-up of these useful processes requires the scale-up of the catalyst, that is, the shaping of the catalyst. Shaped catalysts are essential for the scale-up from powder-based catalyst research to pilot plants. Shaped catalysts can have significantly different properties than powdered catalysts, owing to the use of various additives. In this study, small shaped supports (d:1–2 mm) were used to overcome these limitations. Calcium aluminate-shaped catalysts were prepared via extrusion and applied to a Ni–Co bimetallic catalyst system. According to the screening method, 5Ni1Co (5 wt.% Ni and 1 wt.% Co) catalysts produced synthesis gas with a high CO2 conversion (33 ~ 45%) and H2/CO ratio of 2 in the range of 750–850 ˚C. The high performance of the 5Ni1Co catalyst correlated well with its high concentration of surface hydroxyl groups, as determined by XPS, which likely facilitates the interaction with CO2, particularly on weak basic sites identified by CO2 adsorption.
Graphical Abstract