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Abstract: The manganese-promoted nickel-based catalysts were prepared via wet-incipient impregnation, and tested in auto-thermal reforming (ATR) of ethanol for hydrogen production. The Ni/Al2O3 catalyst, in which Ni existed as NiAl2O4, produced a low H2 yield near 1.85 mol H2/mol ethanol. The Ni–Mn/Al2O3 catalyst showed a better performance in a 30-h test: the conversion of ethanol reached 100%, and a higher H2 yield remained stable near 3.1–3.2 mol H2/mol ethanol. This improvement can be attributed to the promotion of Mn: With Mn, the ilmenite-type NiMnO3 was formed, the reducibility of Ni–Mn/Al2O3 was thus improved, and there were more Ni0 over the surface of catalysts. Moreover, these Ni0 species were stable in the ATR test, as indicated by XRD and XPS. [Copyright &y& Elsevier]

Abstract: Iron-doped LaNiO3 catalysts with a perovskite structure were prepared via self-combustion and tested in auto-thermal reforming (ATR) of ethanol. Characterizations of temperature-programmed surface reaction (TPSR), X-ray diffraction (XRD), physical N2 adsorption, and temperature-programmed reduction (TPR) were carried out. The results indicate that LaNiO3 perovskite structure was successfully formed via self-combustion. With iron-doping in LaNiO3, the perovskite structure still remains, in the form of solid solution La(Ni, Fe)O3, where iron is reducible and the nickel-iron alloy forms after the reduction. In addition, the surface area of the iron-doped samples increased. The TPSR results indicate that with iron-doping, the activity for adsorbed ethanol species is modified and a higher activity for methane transformation is achieved. As a result, an LNF10 sample (LaNi0.90Fe0.10O3) with both nickel and nickel-iron alloy shows better performance in ATR: the ethanol conversion is near 100%, while the selectivity to by-products, such as ethylene, ethane, acetaldehyde and methane, is decreased, and CO2 is the main carbon-containing product; consequently, a hydrogen yield near 3.0 mol H2/mol EtOH is obtained and remains stable in the 30-h test of ATR. [Copyright &y& Elsevier]

Abstract: Auto-thermal reforming (ATR) of bio-ethanol is a promising process for hydrogen production, which can lead to the possibility of directly using low concentration ethanol from fermentation plants without going through the energy-consuming distillation and dehydration processes, saving both energy and cost. Co-based catalysts are active for hydrogen production in ATR, where the hydrogen yield and stability are important factors to be considered. To address the concerns of selectivity and deactivation, iron was introduced into Co-based catalysts via wet-impregnation. The catalysts were characterized with TPR, XRD, XPS, and Raman spectra, and tested in ATR of ethanol. The XPS, XRD, and TPR results show that with iron-promotion, more Co metal is obtained over the catalyst surface, which remains stable during the oxidative atmosphere of ATR. Meanwhile, iron promotes the ethanol dehydrogenation pathway in ATR reactions. This synergic effect contributes to the higher activity and stability of Co-based catalysts in the ATR process: A higher hydrogen yield remains around 3.13mol H2/mol EtOH at 600°C and stays stable in a 30-h test. [Copyright &y& Elsevier]

Abstract: Nanorod alumina-supported Ni–Zr–Fe/Al2O3 catalysts were prepared by co-impregnation, characterized by TEM, TPR, XRD, XPS, and TPD-pyridine, and tested in auto-thermal reforming of ethanol. The characterization results indicate that, with iron and zirconia promotion, the Ni x Fe1−x Al2O4 mixture spinel forms, the valence of the surface Ni species is modified, and the acidity decreases. As a result, during a 30-h test over the Ni–Zr–Fe/Al2O3 catalyst, sintering is restrained, and the selectivity to hydrogen remains around 85.79% without obvious loss, while the un-promoted Ni/Al2O3 shows poor stability and selectivity. [Copyright &y& Elsevier]

Acetic acid (AC) is a representative compound of bio-oil via fast pyrolysis of biomass, and can be processed for hydrogen production via steam reforming (SR). In the current work, the Ni x Co 1− x Mg 6 O 7± δ ( x = 0–1) bimetallic catalysts were prepared via co-precipitation and impregnation, and tested in SR of AC. The reaction results indicate that the monometallic catalysts were deactivated obviously in SR, while the Ni 0.2 Co 0.8 Mg 6 O 7± δ bimetallic catalyst performed better in both activity and stability: not only the conversion of AC remained stable near 100%, but also the H 2 yield maintained stable near 3.1 mol-H 2 /mol-AC. The results of XRD, BET, XPS, TG and TEM indicate that the high catalytic performance of the Ni 0.2 Co 0.8 Mg 6 O 7± δ catalyst can be attributed to 1) resistance to oxidation of active metals, 2) resistance to coking, and 3) stability of structure and electronic properties. [ABSTRACT FROM AUTHOR]