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Effect of rare-earth promoters (Ce, La, Y and Zr) on the catalytic performance of NiO-MgO-SiO2 catalyst in propane dry reforming

Barzegari, F ; Sharif University of Technology | 2022

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  1. Type of Document: Article
  2. DOI: 10.1016/j.mcat.2022.112235
  3. Publisher: Elsevier B.V , 2022
  4. Abstract:
  5. In this contribution, NiO-MgO-SiO2 catalysts containing 3 wt. % of CeO2, La2O3, Y2O3, and Zr2O3 were examined for propane dry reforming at 550-750 °C. The samples were synthesized by a co-precipitation route, followed by a hydrothermal treatment, and characterized by BET, XRD and TPX analyses. The results indicated that the addition of promoters enhanced the metal-support interaction and basic characteristics, while the acidic nature of the promoted catalyst was changed in a different way. The highest propane conversion of 39.6% was observed over Ce-promoter sample, while the un-promoted catalyst possessed a value of 36.8% at 700 °C. Nevertheless, La and Y-promoted catalysts possessed a relatively poor performance, whereby lower CO2 conversion and H2 yield along with the largest amount of by-products. The yield of H2 production decreased in the following order of promoters: Zr>Ce>un-promoted>La>Y. The best catalytic performance observed over ceria-promoted catalysts, supported through the sufficient number of active sites, high oxygen mobility, and redox properties (Ce4+/Ce3+) combined with appropriate acidic/ basic characteristics for reactants activation. The largest amount of coke deposition was detected over the Zr-promoted sample while the Ce-promoted catalyst possessed the lowest carbon formation. The influence of ceria loading on the textural and catalytic properties revealed that the higher loadings of ceria (>3 wt. %) resulted in the formation of ceria island which negatively influenced the catalytic activity. Eventually, 3 wt. % ceria loading was suggested as the optimum loading achieving desirable activity, excellent coke formation resistance, and limited byproducts production over NiO-MgO-SiO2 catalyst. © 2022
  6. Keywords:
  7. Dry reforming: Rare earth promoters ; Catalyst activity ; Catalyst supports ; Catalytic reforming ; Cerium oxide ; Coke ; Deposition ; Hydrogen production ; Lanthanum ; Lanthanum oxides ; Loading ; Magnesia ; Nickel oxide ; Propane ; Rare earths ; Zirconia ; Basic characteristics ; Catalytic performance ; Coke deposition ; Dry reforming ; Dry reforming: rare earth promoter ; Large amounts ; NiO/MgO ; Promoted catalysts ; Rare earth promoter ; ]+ catalyst ; Silica
  8. Source: Molecular Catalysis ; Volume 522 , 2022 ; 24688231 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S2468823122001237