Abstract
The post-reaction Ag surface area distribution of 16 Ag/α-Al2O3 ethylene epoxidation catalysts with varying Ag weight loadings (6.9 – 35 wt%) containing different distributions of Ag particle sizes was correlated with measured ethylene oxide (EO) rates in presence of 3.5 ppm ethyl chloride via a particle size dependent Gaussian rate function. The Gaussian rate function model differs from a description based on average particle size as it accounts for the effects of the breadth of particle size distribution as well as the population of different particle sizes that constitute the Ag particle distribution on measured EO rates. This description of particle size effects in ethylene epoxidation catalysis facilitates accurate prediction of EO rates over a wide range of particle sizes (5–400 nm) and suggests that very small (5–50 nm) and very large Ag particles (>250 nm) have low EO rates (<3 μmol gAg-1 s−1). A narrow Ag particle size distribution centered around ∼130–150 nm would enable operation of ethylene epoxidation with high EO rates and EO selectivity.
Original language | English (US) |
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Pages (from-to) | 99-109 |
Number of pages | 11 |
Journal | Journal of Catalysis |
Volume | 420 |
DOIs | |
State | Published - Apr 2023 |
Externally published | Yes |
Bibliographical note
Funding Information:Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from the NSF through the MRSEC and the NNCI programs. The authors acknowledge Dr. Xinyu Li for assistance with XRD analysis, Prof. David Poerschke and Mr. Atharva Chikhalikar for helping out with heat treatment of γ-Al2O3, Dr. Christopher Ho at Dow Inc. for assistance with parameter estimation in Athena Visual Studio and Dr. Victor Sussman and Dr. Daniel Hickman at Dow Inc. for helpful technical discussions. The authors gratefully acknowledge funding support from Dow through the University Partnership Initiative.
Funding Information:
Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from the NSF through the MRSEC and the NNCI programs. The authors acknowledge Dr. Xinyu Li for assistance with XRD analysis, Prof. David Poerschke and Mr. Atharva Chikhalikar for helping out with heat treatment of γ-Al 2 O 3 , Dr. Christopher Ho at Dow Inc., for assistance with parameter estimation in Athena Visual Studio and Dr. Victor Sussman and Dr. Daniel Hickman at Dow Inc., for helpful technical discussions. The authors gratefully acknowledge funding support from Dow through the University Partnership Initiative.
Publisher Copyright:
© 2023 Elsevier Inc.
Keywords
- Alumina
- Ethylene epoxidation
- Particle size distribution
- Promoters
- Silver