Influence of Ni Loading on Catalytic Activity of NiO/g-Al2O3 for Hydrogenation of Coal Pyrolysis

Shu, Xinqian; Zhang, Lei

doi:10.14233/ajchem.2013.14546

Cited by 2 publications

(1 citation statement)

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“…The XPS spectra of 5Ni/Al2O3(KC, 1073) are summarized in Figure 6 as typical examples. The Ni 2p3/2 peaks were reported to appear at 852, 854-855, and 856-857 eV together with satellite peaks [60][61][62][63][64], which could be attributed to Ni 0 (metal), Ni 2+ of NiO, and Ni 2+ of NiAl2O4 (a spinel compound), respectively. With the present 5Ni/Al2O3(KC, 1073), three peaks were observed at 852.5, 855.0, and 856.1 eV before and after the reaction, as shown in Figure 6, indicating the formation of Ni metal, NiO, and NiAl2O4 species.…”

Section: Comparison Of the Activities Of Various Oxide Catalystsmentioning

confidence: 99%

Higher Activity of Ni/γ-Al2O3 over Fe/γ-Al2O3 and Ru/γ-Al2O3 for Catalytic Ammonia Synthesis in Nonthermal Atmospheric-Pressure Plasma of N2 and H2

et al. 2020

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Developing a novel ammonia synthesis process from N2 and H2 is of interest to the catalysis and hydrogen research communities. γ-Alumina-supported nickel was determined capable of serving as an efficient catalyst for ammonia synthesis using nonthermal plasma under atmospheric pressure without heating. The catalytic activity was almost unrelated to the crystal structure and the surface area of the alumina carrier. The activity of Ni/Al2O3 was quantitatively compared with that of Fe/Al2O3 and Ru/Al2O3, which contained active metals for the conventional Haber–Bosch process. The activity sequence was Ni/Al2O3 > Al2O3 > Fe/Al2O3 > no additive > Ru/Al2O3, surprisingly indicating that the loading of Fe and Ru decreased the activity of Al2O3. The catalytic activity of Ni/Al2O3 was dependent on the amount of loaded Ni, the calcination temperature, and the reaction time. XRD, visual, and XPS observations of the catalysts before the plasma reaction indicated the generation of NiO and NiAl2O4 on Al2O3, the latter of which was generated upon high-temperature calcination. The NiO species was readily reduced to Ni metal in the plasma reaction, whereas the NiAl2O4 species was difficult to reduce. The catalytic behavior could be attributed to the production of fine Ni metal particles that served as active sites. The PN2/PH2 ratio dependence and rate constants of formation and decomposition of ammonia were finally determined for 5.0 wt% Ni/Al2O3 calcined at 773 K. The ammonia yield was 6.3% at an applied voltage of 6.0 kV, a residence time of reactant gases of 0.12 min, and PH2/PN2 = 1.

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