Characterization and catalytic properties of Ni/SiO2 catalysts prepared with nickel citrate as precursor

•The highly-dispersed Ni/SiO2 catalysts were prepared using nickel citrate precursor.•Nickel citrate precursor weakly but sufficiently interacted with SiO2.•NiO–SiO2 interaction increased with calcination temperature as <700 °C.•Ni/SiO2 showed excellent catalytic performance for methane reforming with CO2 + O2.

The Ni/SiO2 catalysts were prepared with nickel citrate precursor by using incipient-wetness impregnation method, characterized by FT-IR, UV-Raman, TG-DTA, XRD, HR-TEM and H2-TPR, and tested in the reaction of methane reforming with CO2 and O2 to produce syngas. The highly-dispersed Ni particles (∼7 nm) on support SiO2 were observed by TEM. FT-IR results indicated that there existed interaction between nickel citrate precursor and SiO2. H2-TPR results demonstrated that, this interaction was enhanced by calcination at high temperature to form strong NiO–SiO2 interaction, and the strong interaction was recovered after repeating oxidation–reduction–oxidation cycle at 700 °C. As a result, the Ni/SiO2 catalysts showed a good activity and super stability without sintering of nickel particles during 36 h reaction on stream.

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