Supported nickel catalysts for low temperature methane steam reforming: comparison between metal additives and support modification
The effect of Ag (1 wt%) and Au (1 wt%) on the catalytic properties of Ni/Al2O3 (7 wt% Ni) for methane steam reforming (MSR) was studied in parallel with the effect of CeO2 (6 wt%) and La2O3 (6 wt%) addition. The addition of 1 wt% Ag to the alumina supported nickel catalyst drastically decreased its catalytic properties at temperatures lower than 600 °C, due to the blockage of metal catalytic centers by silver deposition. The addition of Au and CeO2 (La2O3) to the nickel catalyst improved the methane conversion, CO2 selectivity and hydrogen production at low reaction temperatures (t < 600 °C). At 700 °C under our working conditions, the additives have no important effect in hydrogen production by MSR. The best hydrogen production at low temperatures was obtained for Ni–Au/Al2O3, due to the higher CO2 selectivity, cumulated with slightly higher methane conversion in comparison with Ni/CeO2–Al2O3. At high temperature, Ni/CeO2–Al2O3 is stable for 48 h on stream. Ni–Au/Al2O3 and Ni–Ag/Al2O3 are mainly deactivated due to the temperature effect on Au and Ag nanoparticles and less through coke formation. On Ni/Al2O3 and Ni/La2O3–Al2O3, crystalline, graphitic carbon was deposited after 48 h of reaction leading to catalyst partial deactivation. On the Ni/CeO2–Al2O3 surface, a porous amorphous form of deposited carbon was found, which does not decrease its catalytic activity after 48 h of reaction.
KeywordsLow temperature methane steam reforming Ni–Au catalyst CeO2 promoted Ni catalyst La2O3 promoted Ni catalyst Coke analysis
- 4.Rostrup-Nielsen JR (1984) Catalytic steam reforming. In: Anderson JR, Boudart M (eds) Catalysis: science and technology. Springer, New YorkGoogle Scholar
- 14.Araujo JCS, Zanchet D, Rinaldi R, Schuchardt U, Hori CE, Fiero JLG, Bueno JMC (2008) The effects of La2O3 on the structural properties of La2O3–Al2O3 prepared by sol–gel method and on the catalytic performance of Pt/La2O3–Al2O3 towards steam reforming and partial oxidation of methane. Appl Catal B 84:552–562CrossRefGoogle Scholar
- 22.Lazar MD, Dan M, Mihet M, Almasan V, Rednic V, Borodi G (2011) Hydrogen production by low temperature methane steam reforming using Ag and Au modified alumina supported nickel catalysts. Rev Roum Chim 56(6):637–642Google Scholar
- 23.Dan M, Lazar MD, Rednic V, Almasan V (2011) Methane steam reforming over Ni/Al2O3 promoted by CeO2 and La2O3. Rev Roum Chim 56(6):643–649Google Scholar
- 24.Froment GF, Bischoff KB (1990) Chemical reactor analysis and design, 2nd edn. Willey, New YorkGoogle Scholar