Abstract
Deposition of La2O3and Al2O3on Al2O3-supported Ni catalysts was performed to study their effects on heterogeneous catalysts for the dry reforming of methane (DRM) reaction. An alumina-supported Ni catalyst (Ni/Al2O3, 2 wt % of Ni), synthesized via incipient wetness impregnation, loses ∼87% of its initial activity within 45 h under DRM conditions. While overcoating of Al2O3on this catalyst via atomic layer deposition (ALD) helps stabilize the catalytic activity in long time-on-stream (TOS) tests, this overcoated catalyst is ca. 40 times less active than the uncoated catalyst at peak activity. This Al2O3-overcoated Ni/Al2O3catalyst also exhibits a long induction period (∼20 h) due to the slow reduction of Ni2+within the catalytically inactive nickel aluminate (NiAl2O4) phase, formed by the interaction of metallic Ni with the Al2O3overcoat during pre-DRM treatment at the 700 °C reaction temperature. Here, we report that, while doping small amounts of La (∼0.03 wt %) into the Ni/Al2O3catalyst does not significantly affect the catalytic activity or stability by itself, the addition of ALD-Al2O3on top of the La2O3-promoted Ni catalysts significantly suppresses the long TOS deactivation, helps recover the peak activity of uncoated Ni/Al2O3, and eliminates the DRM induction period. This strategy obtains the stabilization benefits of Al2O3overcoating on Ni/Al2O3while, at the same time, avoiding the formation of undesirable NiAl2O4species.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 10522-10530 |
| Number of pages | 9 |
| Journal | ACS Catalysis |
| Volume | 12 |
| Issue number | 17 |
| DOIs | |
| State | Published - Sep 2 2022 |
Funding
The authors gratefully acknowledge the financial support from an NPRP exceptional grant award NPRP-EP X-100-2-024 from the Qatar National Research Fund (a member of the Qatar Foundation). Y.L. acknowledges the financial support provided by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award number DOE DE-FG02-03ER15457 to the Institute for Catalysis in Energy Processes (ICEP) at Northwestern University. Metal analysis was performed at the Northwestern University Quantitative Bio-element Imaging Center. This work made use of XPS measurement from the Keck-II and XRD facility of Northwestern University supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource, NSF-MRSEC program [DMR-1720139], and IIN. The authors employed the X-ray diffractometers in the IMSERC Crystallography facility at Northwestern University, which has received support from the SHyNE Resource [NSF ECCS-2025633], and Northwestern University. The authors gratefully acknowledge the financial support from an NPRP exceptional grant award NPRP-EP X-100-2-024 from the Qatar National Research Fund (a member of the Qatar Foundation). Y.L. acknowledges the financial support provided by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award number DOE DE-FG02-03ER15457 to the Institute for Catalysis in Energy Processes (ICEP) at Northwestern University. Metal analysis was performed at the Northwestern University Quantitative Bio-element Imaging Center. This work made use of XPS measurement from the Keck-II and XRD facility of Northwestern University supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource, NSF-MRSEC program [DMR-1720139], and IIN. The authors employed the X-ray diffractometers in the IMSERC Crystallography facility at Northwestern University which has received support from the SHyNE Resource [NSF ECCS-2025633] and Northwestern University.
Keywords
- COconversion
- atomic layer deposition
- bimetallic catalysis
- catalyst design
- catalyst stability
- methane reforming
- sintering
- supported catalyst
ASJC Scopus subject areas
- Catalysis
- General Chemistry
