Effects of alumina dissolution and metal ion buffering on the dispersion of alumina supported nickel and ruthenium catalysts

Mieth, J.A.; Schwarz, John H.

doi:10.1016/s0166-9834(00)82324-6

Cited by 24 publications

(3 citation statements)

References 18 publications

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“…This result is in good agreement with the previous results [15,19,20,26]. The surface area of Ru/Al 2 O 3 -H was lower than that of Al 2 O 3 (175 m 2 /g) because some pores of Al 2 O 3 were plugged by the dissolved alumina during the impregnation process [14,19,20,27]. Washing the hydrogen-reduced catalyst resulted in the increase of the surface area by removing some dissolved aluminum.…”

Section: Catalyst Characterizationsupporting

confidence: 92%

Effect of Chlorine on the Chemisorptive Properties and Ammonia Synthesis Activity of Alumina-Supported Ru Catalysts

et al. 2011

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A series of Ru/Al 2 O 3 catalysts were prepared to study the effect of the amount and the origin of residual chlorine on chemisorptive property and the ammonia synthesis activity. The catalysts were characterized by X-ray fluorescence, CO chemisorption, transmission Electron Microscopy, X-ray photoelectron spectroscopy, hydrogen temperature-programmed desorption, hydrogen temperature-programmed reduction. It is found that the presence of chlorine had a limited impact on Ru particle size. Residual chlorine originated from RuCl 3 would not influence on Ru 3d 5/2 binding energy, but chlorine from HCl solution significantly increased Ru 3d 5/2 binding energy. Regardless of their source, the presence of chlorine severely reduced the amount of hydrogen species corresponding to the desorption peak at medium temperature. The inhibition effect of chlorine on hydrogen adsorption was more strong for Ru catalyst with residual chlorine from the RuCl 3 precursor. With a similar amount of residual chlorine, the catalysts with chlorine originated from the RuCl 3 precursor showed much lower catalytic activity than those prepared by impregnation of HCl. These results suggest that chlorine mainly affects the catalytic properties of alumina supported Ru catalysts for ammonia synthesis by selective site blocking.

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Section: Catalyst Characterizationsupporting

confidence: 92%

Effect of Chlorine on the Chemisorptive Properties and Ammonia Synthesis Activity of Alumina-Supported Ru Catalysts

et al. 2011

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“…These results may be correlated with the hydrogen spillover from Ru metal or a larger number of surface groups that appeared during the impregnation process. However, the pH value of RuCl 3 solution is suggested to be low (in the range of 1-3), [38][39][40] but HCl was not an oxidation agent for carbon oxidation. 41 Therefore, the hydrogen spillover phenomenon may be the key factor in increasing the amount of the H 2 O, CH 4 and CO evolution.…”

Section: Catalysis Science and Technology Papermentioning

confidence: 99%

Effect of potassium precursors on the thermal stability of K-promoted Ru/carbon catalysts for ammonia synthesis

Lin

Guo

et al. 2015

Catal. Sci. Technol.

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“…The surface area of Al 2 O 3 is 210.2 m 2 /g, after impregnating of Al 2 O 3 by RuCl 3 aqueous solution followed by hydrogen treatment at 450°C, the surface area of the material decreases to 177.2 m 2 /g, and the pore volume also decreases from 0.562 to 0.489 cm 3 /g. It is well known that the pH of RuCl 3 solution is low (in the range of 1-3) [22,36], thus alumina would dissolve by the following reaction during impregnation [36]:…”

Section: Xrf Analysismentioning

confidence: 99%

Physicochemical Characterization and H2-TPD Study of Alumina Supported Ruthenium Catalysts

Lin

Wang

et al. 2008

Catal Lett

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A series of alumina supported ruthenium catalysts, which prepared by hydrogen treatment or hydrazine reduction, were characterized by N 2 adsorption, X-ray diffraction (XRD), X-ray fluorescence (XRF), CO chemisorption, and Temperature-programmed desorption of hydrogen (H 2 -TPD). In contrast to the samples with conventional hydrogen reduction, there was almost no residual chlorine in the samples using RuCl 3 as precursor with hydrazine treatment. Furthermore, the dissolved aluminum could be removed much more easily in basic solution, which led to the higher BET surface and pore volume of hydrazine-reduction catalysts. Therefore, the active phase (Ru metal) would not be contaminated. Three main peaks, which occurred at about 150, 375, and 650°C, respectively, were observed in the H 2 -TPD profiles of Ru/Al 2 O 3 catalysts with a high amount of residual chlorine. A new peak of desorption hydrogen centering at 240°C, which was completely suppressed by the high amount of residual chlorine, might appear in the profiles of the samples with the washing procedure following hydrogen reduction or hydrazine treatment. The peaks with the desorption temperature lower than 500°C were relative with dissociatively adsorbed hydrogen and spillover hydrogen simultaneity, and the peak at above 500°C was caused by spillover hydrogen and would be stabilized by hydroxyl groups on alumina surface.

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Effects of alumina dissolution and metal ion buffering on the dispersion of alumina supported nickel and ruthenium catalysts

Cited by 24 publications

References 18 publications

Effect of Chlorine on the Chemisorptive Properties and Ammonia Synthesis Activity of Alumina-Supported Ru Catalysts

Effect of Chlorine on the Chemisorptive Properties and Ammonia Synthesis Activity of Alumina-Supported Ru Catalysts

Effect of potassium precursors on the thermal stability of K-promoted Ru/carbon catalysts for ammonia synthesis

Physicochemical Characterization and H2-TPD Study of Alumina Supported Ruthenium Catalysts

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