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A series of Ni-CeO2catalysts were prepared by co-precipitation method with Na2CO3,NaOH,and mixed precipitant(Na2CO3:NaOH;1:1 ratio)as precipitant,respectively.The effect of the precipitants on the catalytic performance,physical and chemical properties of Ni-CeO2catalysts was investigated with the aid of X-ray diffraction(XRD),Brumauer-Emmett-Teller method(BET),Fourier-transform infrared spectroscopy(FT-IR),thermogravimetry(TG),and H2-TPR characterizations.The Ni-CeO2catalysts were examined with respect to their catalytic performance for the reverse water-gas shift reaction,and their catalytic activities were ranked as:Ni-CeO2-CP(Na2CO3:NaOH=1:1)>Ni-CeO2-CP(Na2CO3)>Ni-CeO2-CP(NaOH).Correlating to the characteristic results,it was found that the catalyst prepared by co-precipitation with mixed precipitant(Na2CO3:NaOH;1:1 ratio)as precipitant had the most amount of oxygen vacancies accompanied with highly dispersed Ni particles,which made the corresponding Ni-CeO2-CP(Na2CO3:NaOH=1:1)catalyst exhibit the highest catalytic activity.While the precipitant of Na2CO3or NaOH resulted in less or no oxygen vacancies in Ni-CeO2catalysts.As a result,Ni-CeO2-CP(Na2CO3)and Ni-CeO2-CP(NaOH)catalysts presented poor catalytic performance.
A series of Ni-CeO2catalysts were prepared by co-precipitation method with Na2CO3, NaOH, and mixed precipitant (Na2CO3: NaOH; 1: 1 ratio) as precipitant, respectively. The effect of the precipitants on the catalytic performance, physical and chemical properties of Ni-CeO2catalysts was investigated with the aid of X-ray diffraction (XRD), Brumauer-Emmett-Teller method (BET), Fourier-transform infrared spectroscopy (FT- IR), thermogravimetry (TG), and H2-TPR characterizations. The Ni-CeO2catalysts were examined with respect to their catalytic performance for the reverse water-gas shift reaction, and their catalytic activities were ranked as: Ni-CeO2-CP (Na2CO3: NaOH = 1: 1)> Ni-CeO2-CP Na2CO3)> Ni-CeO2-CP (NaOH). Correlating to the characteristic results, it was found that the catalyst prepared by co-precipitation with mixed precipitant (Na2CO3: NaOH; 1: 1 ratio) as precipitant had the most amount of oxygen vacancies accompanied with highly dispersed Ni particles, which made the corresponding Ni-CeO2-CP (Na2CO3: NaOH = 1: 1) catal yst exhibit the highest catalytic activity. Temperature-precipitated of Na2CO3or NaOH resulted in less or no oxygen vacancies in Ni- CeO2catalysts. As a result, Ni-CeO2-CP (Na2CO3) and Ni- CeO2-CP performance.