Abstract
This study investigates changes in dispersion with time-on-stream of a Ni catalyst coated with alumina by Atomic Layer Deposition (ALD) in Dry Reforming of Methane (DRM) conditions. A 20 wt% commercial Ni catalyst is coated with 5, 10, and 20 ALD cycles and tested for DRM at 650 °C, 1 atm for 40 h. Using an in-situ H2–CO pulse chemisorption technique, it is found that the rate of decline in catalyst dispersion is more rapid in the uncoated catalyst (~0.11%h−1) than 5-ALD catalyst (~0.025%h−1). TEM images before and after reaction show that the average particle size for the uncoated catalyst increases from 8.5 nm to 24.5 nm, indicating sintering, whereas the 5-ALD catalyst retained the initial particle size. The reduced particle size also explains the 50% reduction in carbon formation-rate in the 5-ALD catalyst. The developed sequential H2–CO chemisorption technique reliably measures in-situ dispersion in uncoated and ALD coated catalysts with exposed active sites.
Original language | English |
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Pages (from-to) | 12835-12848 |
Number of pages | 14 |
Journal | International Journal of Hydrogen Energy |
Volume | 45 |
Issue number | 23 |
DOIs | |
Publication status | Published - Apr 28 2020 |
Keywords
- Atomic layer deposition (ALD)
- Chemisorption
- Dispersion
- Methane dry reforming (DRM)
- Ni catalyst
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Condensed Matter Physics
- Energy Engineering and Power Technology