Dry reforming of methane over Zr- and Y-modified Ni/Mg/Al double-layered hydroxides

Abstract

Zr-and Y-promoted Ni/Mg/Al double-layered hydroxides were investigated in dry reforming of methane, DRM (10% CH4, CH4/CO2=1, GHSV=20,000 h-1) for the first time. Modification of the double-layered hydroxides with 5 wt% of zirconium and 0.4 wt% of yttrium resulted in the formation of ZrO2-Y2O3 solid solution, which largely contributed to the enhancement of catalyst's stability with time-on-stream at 700 °C in DRM. Also, the modified catalyst demonstrated the limitation of the reverse WGS reaction, as confirmed by powder XRD due to the absence of the rhombohedral hydrotalcite structure.

Ce- and Y-Modified Double-Layered Hydroxides as Catalysts for Dry Reforming of Methane: On the Effect of Yttrium Promotion

“…Similar positive effects were reported in other Y-promoted materials tested in DRM [18,[23][24][25][26]. Moreover, Zr-modified hydrotalcites doped with yttrium (0.2-0.6 wt.%) showed good catalytic performance [18]. In this study, the promotion with 0.4 wt.% of Y led to the better activity and stability (as compared to the Y-free material) that was linked to the formation of solid solution of ZrO 2 -Y 2 O 3 , which enhanced reduction of bulk NiO.…”

“…In our previous study we showed that Y (0.6-1.5 wt.%) increased specific surface area of Ni-DLHs, led to smaller Ni crystallites and enhanced dispersion of active sites as compared to the unpromoted catalyst [4]. Similar positive effects were reported in other Y-promoted materials tested in DRM [18,[23][24][25][26]. Moreover, Zr-modified hydrotalcites doped with yttrium (0.2-0.6 wt.%) showed good catalytic performance [18].…”

“…Yttrium has also been reported as a promising promoter, especially in dry reforming of methane [4,18,[23][24][25]. In our previous study we showed that Y (0.6-1.5 wt.%) increased specific surface area of Ni-DLHs, led to smaller Ni crystallites and enhanced dispersion of active sites as compared to the unpromoted catalyst [4].…”

“…After the thermal treatment in hydrogen, nickel oxides are reduced to metallic nickel, which is located on the surface of the catalyst and can react with CH 4 in DRM [3]. This kind of catalysts were reported as active and selective in dry reforming of methane [8][9][10][11], however, a significant improvement in their performance can be observed after promotion with metals, such as Ce, Zr, Y, La, or Zn [4,[12][13][14][15][16][17][18][19]. Modification with ceria was described as beneficial in dry reforming of methane, due to oxygen storage capacity and redox properties of Ce [13][14][15][20][21][22].…”

Fibrous spherical Ni‐M/ZSM‐5 (M: Mg, Ca, Ta, Ga) catalysts for methane dry reforming: The interplay between surface acidity‐basicity and coking resistance

“…As we recently reviewed, the nature of the support has a strong influence on the activity, selectivity and stability of supported Ni catalysts in DRM reaction . Support materials such as SiO 2 , KCC‐1, KIT‐6, Al 2 O 3 , CeO 2 , perovskites and zeolites have been investigated in DRM. In general, zeolites are microporous crystalline aluminosilicates.…”