Thermogravimetrische Untersuchung der ZnO + H2-Reaktion in strömendem Wasserstoff

Hegedüs, A. J.; Kiss, A.

doi:10.1007/bf01223006

Cited by 5 publications

(5 citation statements)

References 6 publications

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“…In contrast, the reaction rate of Z2T remained first order. As discussed in Section 3.1, similar inhibitory effects on , ZnO reduction by water vapor have been observed by others(Hegedus and Kiss, 1966;Flytzani-Stephanopoulos et al, 1987).…”

supporting

confidence: 80%

“…The self-inhibitory effect produced by the larger product H,O concentrations in the earlier study can explain the lower reported values of reduction rates. Hegedus and Kiss (1966) observed a decrease in the reduction rate as the mole fraction of H20 was varied from 7.0~10'~ to 5.9~10'~ %. In our previous work, the product H20 mole fraction was 6.5~10'~ % based on Table 33 Values of k, for solid reduction in the presence of H201…”

Section: )mentioning

confidence: 88%

“…The intrinsic reduction kinetics of Zn-Ti-0 solids as a function of =/Ti ratio and crystalline phases were investigated to determine the mechanism of reduction and how titanium dioxide interacts to inhibit reduction. The effect of H20 was examined because not only is it a major component (10-50%) in coal gases, but also because of its inhibitory effects on 2 x 1 0 reduction (Hegedus and Kiss, 1966; ~~-S t e p h a n o p o u l o s et al, 1987).…”

Section: Description Of Project Tasksmentioning

confidence: 99%

See 2 more Smart Citations

Mechanistic and kinetic studies of high-temperature coal gas desulfurization sorbents. Final report, July 1988--July 1991

Lew¹,

Flytzani‐Stephanopoulos²,

Sarofim³

1991

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This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or impiied, or assumes any legai liabiiity or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privateiy owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

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supporting

confidence: 80%

Section: )mentioning

confidence: 88%

Section: Description Of Project Tasksmentioning

confidence: 99%

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Mechanistic and kinetic studies of high-temperature coal gas desulfurization sorbents. Final report, July 1988--July 1991

Lew¹,

Flytzani‐Stephanopoulos²,

Sarofim³

1991

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“…Temperature-programmed reduction (TPR) was performed to give further insight into the reducibility of the system. Pure bulk ZnO is only reduced at temperatures above 700 K . In our study we only investigated the temperature range up to 623 K, as this is the range relevant for the studied reactions and will give information about defect formation such as oxygen vacancies.…”

Section: Resultsmentioning

confidence: 99%

Promoting Strong Metal Support Interaction: Doping ZnO for Enhanced Activity of Cu/ZnO:M (M = Al, Ga, Mg) Catalysts

et al. 2015

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The promoting effect of Al, Ga, and Mg on the support in Cu/ZnO catalysts for methanol synthesis has been investigated. Different unpromoted and promoted ZnO supports were synthesized and impregnated with Cu metal in a subsequent step. All materials, supports, and calcined and activated catalysts were characterized by various methods, including contactless (microwave) conductivity measurements under different gas atmospheres. Small amounts of promoters were found to exhibit a significant influence on the properties of the oxide support, concerning textural as well as electronic properties. We found correlations between the conductivity of the ZnO support and the activity of the catalyst in the reverse water-gas shift reaction (rWGS) as well as in methanol synthesis. In rWGS the activation energy and reaction order in H₂ are decreased upon promotion of the ZnO support with the trivalent promoters Al³⁺ and Ga³⁺, indicating an electronic promotion. In methanol synthesis, results point to a structural promotion by Al³⁺ and Ga³⁺. A detrimental effect of Mg²⁺ doping was observed in both reactions. This effect is discussed in the context of the reducibility of ZnO under reaction conditions, which can be tuned by the promoter in different ways. The reducibility is seen as a critical property for the dynamic metal support interaction of the Cu/ZnO system

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“…The influence of surface preparation on Ca oxidation kinetics (13) and 20 vapor on the dehydration kinetics of CaHP04-2H20 (117) and kaolinite (68) has been reported. In a study of the reduction of ZnO by H2 (173), the initial reduction temperature and reduction rate were functions of impurities and the ratio of partial pressures of H20 and H2. Decomposition kinetic studies have been made with CaC204 (142), Mn(N03)2 (171), MgS04'H20 (177), phenol-formaldehyde condensates (14,127), and cellulose, with and without modification by NH4H2P04 (5).…”

Section: Thermogravimetric Analysis (Tga)mentioning

confidence: 99%

Thermal analysis

Murphy¹

1968

Anal. Chem.

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Thermogravimetrische Untersuchung der ZnO + H2-Reaktion in strömendem Wasserstoff

Cited by 5 publications

References 6 publications

Mechanistic and kinetic studies of high-temperature coal gas desulfurization sorbents. Final report, July 1988--July 1991

Mechanistic and kinetic studies of high-temperature coal gas desulfurization sorbents. Final report, July 1988--July 1991

Promoting Strong Metal Support Interaction: Doping ZnO for Enhanced Activity of Cu/ZnO:M (M = Al, Ga, Mg) Catalysts

Thermal analysis

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