Effect of Pr addition on the properties of Ni/Al2O3 catalysts with an application in the autothermal reforming of methane

•Pr modified Ni/γ-Al2O3 have been used in the autothermal reforming of methane.•Pr modification reduces the nickel particle size and coke deposition of the catalyst.•The introduction of Pr improves the activity and stability of the catalyst.•Ni/Pr-Al2O3 catalysts exhibit good activity and stability in the reaction.

Ni/xPr-Al2O3 (x = 5, 10, 15, 20 wt%) catalysts with an application in autothermal reforming of methane were prepared by sequential impregnation synthesis; its catalytic performance was evaluated and compared with that of Ni/γ-Al2O3 catalyst; the physicochemical properties of the catalysts were characterized by X-ray diffraction (XRD), Transmission electron microscope (TEM), X-Ray Photoelectron Spectrometer (XPS), Thermo Gravimetric Analyzer (TGA) and H2-temperature programmed reduction techniques (TPR). The results showed that Pr addition promoted the reduction of nickel particle size on the surface. TPR experiments suggested a heterogeneous distribution of nickel oxide particles over xPr-Al2O3 supports and the promotion of NiO reduction by Pr modification. The CH4 conversion increased with elevating levels of Pr addition from 5% to 10%, then decreased with Pr content from 10% to 20%. For the stability catalytic tests, Ni/xPr-Al2O3 catalysts maintained the high activity after 48 h while Ni/Al2O3 had a significant deactivation.

Graphical abstractPr modified Ni/γ-Al2O3 was prepared and used in the autothermal reforming of methane. The introduction of praseodymium oxide improves the activity and stability of the catalyst. Pr modification reduces the nickel particle size and coke deposition of the catalyst.Figure optionsDownload full-size imageDownload as PowerPoint slide