The Kinetics of Sintering of Platinum Supported on Alumina

Herrmann, Reimer; Adler, Stephen F.; Goldstein, Mark; DeBaun, Robert M.

doi:10.1021/j100829a019

Cited by 90 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These conclusions have been confirmed by Maat and Moscou (1965) and by Zaidman et al (1969). The kinetic equation suggested by Herrmann et al (1961) to describe the evolution of the exposed surface area S of the metal is of the form dS -= -K P dt Analyzing the available experimental results of Maat and Moscou (1965), Gruber (1962) and Hughes et al (1962) we have observed that in reality where the range of the exponent n is between 2 and 8.…”

Section: Conclusion and Significancementioning

confidence: 96%

“…Herrmann et al (1961) subjected various samples of Pt-on-alumina catalyst to a series of heat treatments and used hydrogen chemisorption and X-ray diffraction to obtain information about the state of platinum. They concluded that platinum was present in the original catalyst in a highly dispersed form and that heat treatment caused the formation of platinum crystallites and their growth.…”

Section: Conclusion and Significancementioning

confidence: 99%

“…They found that the exposed platinum area followed a second-order reaction, which, according to the present considerations shows a sintering controlled decay. Herrmann et al (1961) Table 3.…”

Section: O M P a R I S O N With E X P E R I M E N Tmentioning

confidence: 99%

See 2 more Smart Citations

Kinetics of crystallite sintering during heat treatment of supported metal catalysts

1973

View full text Add to dashboard Cite

Models are developed to describe sintering of metal crystallites during heat treatment. The growth rate of such crystallites is assumed to depend upon particle migration over the surface of the support as well as on the rate the colliding particles merge (sinter) into a single unit. The theory predicts that the rate of decay of exposed metal surface area S is given as in Equation (1a). The exponent n is related to the assumed size dependence of the diffusion coefficients or of the rate constant of the merging process. It varies from 4 to 8 for diffusion controlled decay and it is less than 3 for sintering controlled decay, that is, when the rate controlling step is the merging of two colliding particles. Diffusion control is associated with strong interactions between the metal and the support, but in sintering control there is a weaker metal‐support interaction.

show abstract

Section: Conclusion and Significancementioning

confidence: 96%

Section: Conclusion and Significancementioning

confidence: 99%

See 1 more Smart Citation

Kinetics of crystallite sintering during heat treatment of supported metal catalysts

1973

View full text Add to dashboard Cite

show abstract

“…The catalyst is often dried and/or calcined followed by a reduction treatment in H2 gas to reduce the Pt and form small clusters. One common and long used characterization tool used to determine the Pt cluster size and dispersion is the measurement of hydrogen chemisorption [9,10]. Before 1980, direct measurement of such small particles was not possible such that correlations between hydrogen chemisorption and X-ray diffraction (XRD) were made only on large agglomerated clusters.…”

Section: Fundamentals Of Platinum For Catalytic Reformingmentioning

confidence: 99%

Advanced characterization for industrial catalysis applications

Kelly

Sinkler

et al. 2019

Chinese Journal of Catalysis

View full text Add to dashboard Cite

“…Various samples of Pt-Al 2 O 3 -Cl reforming catalyst were subjected to a series of heat treatments and studied by several characterization techniques [Herrmann et al, 1961] and Pt was present in the original catalyst in a highly dispersed, perhaps ionic, form and that heat treatment causes the formation of Pt crystallites, and not merely their growth. Moscou,1965 andGruber, 1962].…”

Section: Wwwintechopencommentioning

confidence: 99%