Nickel Supported on Mesoporous Alumina for Dry Reforming of Methane: Combustion Method.

Ni catalysts supported on ordered mesoporous alumina (OMA) were prepared by EISA method and calcined under air and Ar atmospheres. Both catalysts showed stable performance for the dry reforming of methane for 24 h, however the catalytic activity of Ar calcined catalyst was relatively lower than that in the air calcined one. It was found that the carbon (C ß ) layer around nickel particles was observed for the Ar calcined catalyst after dry reforming of methane. The encapsulating carbon species in the Ar calcined catalyst lowering the mass transfer rate of feeds led to lower performance, but no whisker carbon was observed. In the case of the air calcined catalyst, whisker carbon (C(v)) which is inactive during dry reforming was accumulated on the catalyst, and it resulted in catalyst breakdown and pressure drop during the reaction.

The Effect of Fe in Perovskite Catalysts for Steam CO2 Reforming of Methane.

In this work, La0.95Sr0.05Ni(1-x)Fe(x)O3 catalysts were prepared by modified EDTA-cellulose method and the catalysts were characterized by various techniques such as N2 physisorption, TPR, XRD, SEM, TEM-EDS and TG analysis. La00.95Sr0.05Ni0.5Fe0.5O3 catalyst showed better catalytic performance under the reaction conditions of 900 degrees C, 21 bar and feed molar ratio of CH4:CO2:H20 = 1:0.7:1.5. It is considered that the dilution effect on nickel prevented the formation of large monometallic ensembles that favour the carbon deposition in reforming reactions, and the mean metallic particle size of Ni decreased with increasing substitution rate in B site. Therefore, partial substitution of Fe in B site enhances the dilution effect and induces a reaction between CO2 and La2O3, thereby resisting the carbon deposition and increasing CO2 conversion.

Ni/MgO-MgAl2O4 Catalysts with Bimodal Pore Structure for Steam-CO2-Reforming of Methane.

The bead type MgO-MgAl2O4 catalyst supports with bimodal pore structures were fabricated via an extrusion molding of gels derived from the precursor mixture of mesoporous MgO particles and aluminum magnesium hydroxide, followed by heat treatment. To investigate the effect of macro pore structures on the catalytic activity of the Ni/MgO-MgAl2O4 catalysts in the steam and carbon dioxide reforming of methane (SCR), two kinds of the catalysts with largely different macro pore volumes and sizes but nearly the same meso pore volume and size were compared. The bimodal catalyst with a large macro pore size and volume exhibited a highly enhanced CO2 conversion from 22.3 to 37.1% but a slightly reduced CH4 conversion from 95.3 to 92.1% at the same feed ratio. The SCR results show that the large macro pores can lead to a highly enhanced mass transfer rate of CO2 absorption into the pore channels of the magnesium alumina spinel.

Hydrogenolysis of Glycerol to 1,2-Propanediol Over Clay Based Catalysts.

1,2-propanediol (1,2-PDO) is one of the promising product among the valuable products derived from glycerol and it can be obtained by the catalytic hydrogenolysis of glycerol. Copper-supported clay-based catalysts were prepared with different pore sizes using various ratios of kaolin, Mg, and Al by coprecipitation and applied in the selective hydrogenolysis of glycerol to 1,2-PDO. In recent research, variations of pore volume and pore size could affect the diffusion of reagents within the catalyst due to the collision between reagents or pore wall and reagents. It changes selectivities of each product in hydrogenolysis of glycerol reaction. The physico-chemical properties of the catalysts were analyzed by XRD, N2 physisorption, TPR, CO2-TPD, SEM, and a mercury porosimeter. The Cu/TALCITE 4 catalyst showed 98% 1,2-PDO selectivity with 65% glycerol conversion under the optimized condition of 190 degrees C, 25 bar, and 20 wt% glycerol aqueous solution. It was found that the basic strength and meso-macro pore structure of the catalysts play an important role in glycerol conversion and 1,2-PDO selectivity.

Preparation and characterization of Ni-based perovskite catalyst for steam CO2 reforming of methane.

Steam CO2 reforming of methane was investigated over Ni-based perovskite catalyst to produce desired H2/CO ratio by adjusting the feed ratio of CH4, CO2 and H2O for floating GTL process application. La modified perovskites were prepared by the Pechini method and calcined in air and the Ni-based catalysts were prepared by dispersing Ni on the La modified perovskite by an incipient wetness impregnation. The catalysts before and after the reaction were characterized by N2 physisoprtion, CO chemisoprtion, XRD, TPR and SEM techniques. To control desired H2/CO ratio, simulation for SCR was carried out by Aspen plus, and product distribution for SCR was investigated in a fixed bed reactor system using feed ratio estimated by simulation. The Ni-based perovskite catalysts were found to give CH4 and CO2 conversions of up to 82% and 60% respectively to yield a H2/CO product ratio close to 2.