Activity, Surface Area, and Weight Loss Correlations for Hydrous Ferric Oxide Catalyst

Gini, D.; Finch, F.T.; Wald, Joachim; Barrick, P. L.

doi:10.1007/978-1-4757-0528-7_21

Cited by 3 publications

(4 citation statements)

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“…Their data indicate that the high temperatures reduced the catalytic activity to lower levels, but the residual activity was still fitting the requirements. The mass loss of water with time and temperature arising from the dehydration process was similar to that observed by Gini et al [56] in an earlier study.…”

Section: Iron Oxides and Oxy-hydroxidessupporting

confidence: 88%

Isotopic and other influences on the realization of the triple point of hydrogen

et al. 2005

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Within an international collaboration of the eight metrological institutes represented by the authors, the dependence of the triple-point temperature of equilibrium hydrogen on the deuterium content at low concentrations has been precisely determined so that the uncertainty in realizing the triple point as a temperature fixed point might be reduced by nearly one order of magnitude. To investigate the thermodynamic properties of the hydrogen-deuterium mixtures and to elucidate the factors that influence the melting temperature, 28 sealed fixed-point cells have been filled and measured, and some of these have been compared with an open-cell system. Hydrogen gas with a deuterium content ranging from 27.2 µmol D/mol H to 154.9 µmol D/mol H was studied using cells containing five different types of spin-conversion catalyst, with different catalyst-to-liquid volume ratios (a few per cent to more than 100%) and of different designs. The latter consideration is especially influential in determining the thermal behaviour of the cells and, thus, the temperature-measurement errors. The cells were measured at the eight participating institutes in accordance with a detailed protocol that facilitates a direct comparison of the results. Through analysis of the measurements, significant inter-institute deviations due to different measurement facilities and methods have been ruled out with respect to the determination of both the melting temperatures and the thermal parameters of the cells. The uncertainty estimates for the determination of the deuterium content have been verified by including isotopic analysis results from four different sources. The slope of the dependence of the triple-point temperature of equilibrium hydrogen isotopic mixtures on the deuterium content has been deduced from the melting temperatures of those sample portions not in direct contact with the catalysts. Evaluation of the data using different mathematical methods has yielded an average value of 5.4 2 µK per µmol D/mol H, with an upper bound of the standard uncertainty of 0.3 1 µK per µmol D/mol H. This is close to the literature value of 5.6 µK per µmol D/mol H that was obtained at higher deuterium concentrations.

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Section: Iron Oxides and Oxy-hydroxidessupporting

confidence: 88%

Isotopic and other influences on the realization of the triple point of hydrogen

et al. 2005

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“…The cell and catalyst were then purged several times with D2O vapour. Though it was reported that temperatures higher than 250 O C would deactivate the catalyst and reduce by as much as ten times the active surface [28]. this catalyst was found to be good enough for our purposes.…”

mentioning

confidence: 77%

“…5 was completed 7 h after cooldown). This is probably due to the fact that the catalyst had been heated up to 450 "C in the cells for proper conditioning, a temperature which is known to be too high for good efficiency [28].…”

Section: E) Equilibrium Deuteriummentioning

confidence: 99%

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The Triple-point Temperature of Pure Equilibrium Deuterium

Pavese

McConville

1987

Metrologia

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A study specifically intended to measure the triple-point temperature of both n-D2 and e-D2 containing a volume fraction of HD not higher than 0.0001 has been completed. It was performed by measuring samples of gas in metal sealed cells. The cells, after being checked for a non-increasing HD contamination within the stated limits, were filled by directly connecting them to the outlet of a thermal-diffusion column for isotopic separation, known to produce D2 with a HD volume fraction not larger than 0.00003. In the case of e-D2, additional studies were performed on the effect of deuterating the catalyst or on high-temperature activation of the catalyst. Results proved that it is possible to obtain good results for e-D2 with partially deuterated catalyst, but this does not allow a reliable control of the contamination. An alternative procedure to full deuteration has been found, which uses commercial hydrous ferric oxide heated to about 400 °C, and commercially available deuterium, produced by isotopic separation and showing a purity better than 99.99%. Temperature values (18.7327 ± 0.0003) K for n-D2 and (18.6983 ± 0.0003) K for e-D2 on NPL-IPTS-68 were obtained at the liquidus point; the best thermodynamic values for these triple points are (18.7232 ± 0.001) K and (18.6888 ± 0.001) K respectively; e-D2 can be used as a first-quality temperature reference point.

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Review of hydrogen ortho–para conversion: experimental data and reaction kinetics

Jiao,

Al Ghafri,

O'Neill

et al. 2024

React. Chem. Eng.

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Activity, Surface Area, and Weight Loss Correlations for Hydrous Ferric Oxide Catalyst

Cited by 3 publications

References 4 publications

Isotopic and other influences on the realization of the triple point of hydrogen

Isotopic and other influences on the realization of the triple point of hydrogen

The Triple-point Temperature of Pure Equilibrium Deuterium

Review of hydrogen ortho–para conversion: experimental data and reaction kinetics

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