摘要
Effects of A-site cation substitution and B-site active metal doping-segregation on physicochemical properties of Ni-doped perovskite-structured LnFe 0.7 Ni 0.3 O 3 (Ln = La, Nd, Sm, Eu) catalysts and their catalytic performance for dry reforming of ethane (DRE) were studied. The DRE activity follows the trend: NdFe 0.7 Ni 0.3 O 3 > SmFe 0.7 Ni 0.3 O 3 > EuFe 0.7 Ni 0.3 O 3 > LaFe 0.7 Ni 0.3 O 3 . The doping-segregation process of Ni was demonstrated by in-situ X-ray Diffraction (XRD) and X-ray Absorption Fine Structure (XAFS) measurements, which significantly improves the dispersion of Ni and enhance the interaction between metal and support. The results of temperature-programmed surface reactions (TPSR) and pulse reactions indicate that oxygen vacancies generated by the exsolution of Ni play an important role in the elimination of coke and shift the product from surface carbon to gaseous CO. According to the in-situ Raman experiments, the superior catalytic stability (no coke deposition or activity loss over 100 h) of NdFe 0.7 Ni 0.3 O 3 is ascribed to its strong resistance towards carbon deposition.
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