Sung Min Kim

Last Name

Kim

First Name

Sung Min

ORCID

0000-0001-6602-1320

Show all metadata

Search Results

Publications 1 - 10 of 12

Bi-functional Ru/Ca3Al2O6–CaO catalyst-CO2 sorbent for the production of high purity hydrogen via sorption-enhanced steam methane reforming
Kim, Sung Min; Abdala, Paula M.; Hosseini, Davood; et al. (2019)
Catalysis Science & Technology
Sorption-enhanced steam methane reforming (SE-SMR) combines steam methane reforming and a CO2 abstraction reaction to yield high purity hydrogen. In this work, we report on the development of a bi-functional catalyst–sorbent containing Ru as the reforming catalyst and CaO as the solid CO2 sorbent via a citrate sol–gel route. The material contains CaO, a structural stabilizer (Ca3Al2O6) and Ru nanoparticles (∼5 nm, 3 wt%) that are formed upon reduction in H2. This new material was found to outperform significantly the benchmarks Ni–CaO and Ru/limestone in terms of yield of high-purity hydrogen and coke resistance. Using highly active Ru nanoparticles for the SMR allowed to maximize the weight fraction of the CO2 sorbent CaO, hence increasing significantly the CO2 capture capacity of the material. This favorable characteristic of the material led to an appreciably extended pre-breakthrough duration. In addition, we demonstrate that the material developed was very stable over multiple SE-SMR/regeneration cycles. The excellent cyclic stability is ascribed to the presence of Ca3Al2O6 that stabilized effectively the porous structure of the material against sintering.
Development of effective sorbents and catalysts for the capture and conversion of CO2
Kim, Sung Min (2019)
In Situ XANES/XRD Study of the Structural Stability of Two-Dimensional Molybdenum Carbide Mo2CT x: Implications for the Catalytic Activity in the Water-Gas Shift Reaction
Deeva, Evgeniya B.; Kurlov, Alexey; Abdala, Paula M.; et al. (2019)
Chemistry of Materials
Of Glasses and Crystals: Mitigating the Deactivation of CaO-Based CO₂ Sorbents through Calcium Aluminosilicates
Krödel, Maximilian; Leroy, César; Kim, Sung Min; et al. (2023)
JACS Au
CaO-based sorbents are cost-efficient materials for high-temperature CO₂ capture, yet they rapidly deactivate over carbonation-regeneration cycles due to sintering, hindering their utilization at the industrial scale. Morphological stabilizers such as Al₂O₃ or SiO₂ (e.g., introduced via impregnation) can improve sintering resistance, but the sorbents still deactivate through the formation of mixed oxide phases and phase segregation, rendering the stabilization inefficient. Here, we introduce a strategy to mitigate these deactivation mechanisms by applying (Al,Si)Oₓ overcoats via atomic layer deposition onto CaCO₃ nanoparticles and benchmark the CO₂ uptake of the resulting sorbent after 10 carbonation-regeneration cycles against sorbents with optimized overcoats of only alumina/silica (+25%) and unstabilized CaCO₃ nanoparticles (+55%). ²⁷Al and ²⁹Si NMR studies reveal that the improved CO₂ uptake and structural stability of sorbents with (Al,Si)Oₓ overcoats is linked to the formation of glassy calcium aluminosilicate phases (Ca,Al,Si)Oₓ that prevent sintering and phase segregation, probably due to a slower self-diffusion of cations in the glassy phases, reducing in turn the formation of CO₂ capture-inactive Ca-containing mixed oxides. This strategy provides a roadmap for the design of more efficient CaO-based sorbents using glassy stabilizers.
Development of Coke-and sintering-resistant Ni/SiO2-based dry reforming catalyst by depositing a thin layer of AI2O3 via ALD
Kim, Sung Min; Armutlulu, Andac; Abdala, Paula M.; et al. (2017)
Development of an effective bi-functional Ni-CaO catalyst-sorbent for the sorption-enhanced water gas shift reaction through structural optimization and the controlled deposition of a stabilizer by atomic layer deposition
Kim, Sung Min; Armutlulu, Andac; Kierzkowska, Agnieszka M.; et al. (2020)
Sustainable Energy & Fuels
The integration of a CaO-based CO2 sorbent into catalytic schemes to remove CO2 from the product stream provides an effective means to reduce greenhouse gas emissions of chemical processes and to improve the yield and purity of the desired product. A key requirement for such so-called sorbent-enhanced processes is the availability of cyclically stable CO2 sorbent. To this end, we have developed CaO-based CO2 sorbents that combine favourable structural features and a high thermal stability by introducing a thin, conformal layer of Al2O3 (forming Ca3Al2O6 with CaO upon calcination) by atomic layer deposition. The structure and pore volume of the sorbent were found to play a key role in its CO2 capture. Functionalizing such CO2 sorbents with Ni nanoparticles yielded a highly effective bi-functional material for the sorption-enhanced water-gas shift (SE-WGS) reaction. The material showed a high yield of hydrogen of high purity and minimal CO slip over several cycles of repeated SE-WGS/regeneration operation.
Reversible Exsolution of Dopant Improves the Performance of Ca2Fe2O5 for Chemical Looping Hydrogen Production
Hosseini, Davood; Donat, Felix; Abdala, Paula M.; et al. (2019)
ACS Applied Materials & Interfaces
Exsolution of Metallic Ru Nanoparticles from Defective, Fluorite-Type Solid Solutions Sm2RuxCe2–xO7 To Impart Stability on Dry Reforming Catalysts
Naeem, Muhammad A.; Abdala, Paula M.; Armutlulu, Andac; et al. (2020)
ACS Catalysis
A key challenge in the catalytic conversion of CH4 and CO2 into a synthesis gas (CO and H2) via the dry reforming of methane (DRM) is the development of stable catalysts. We demonstrate that the reductive exsolution of metallic Ru from fluorite-type solid solutions Sm2RuxCe2–xO7 (x = 0, 0.1, 0.2, 0.4) yields catalysts with high activity and remarkable stability for the DRM. The catalysts feature Ru(0) nanoparticles about 1–2 nm in diameter that are uniformly dispersed on the surface of the resulting oxide support. The exsolved material was investigated by synchrotron X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS at Ru, Sm, and Ce K-edges), Raman spectroscopy, and transmission electron microscopy. In situ XAS-XRD experiments revealed that the exsolution of metallic ruthenium is accompanied by a rearrangement of the oxygen vacancies within the lattice. The catalysts derived through exsolution outperform (stable over 4 days) the reference catalysts prepared by wetness impregnation and sodium borohydride reduction. The superior performance of the exsolved catalysts is explained by their high resistance to sintering-induced deactivation owing to the stabilizing metal–support interaction in this class of materials. It is also demonstrated that the Ru nanoparticles can undergo redissolution (in air at 700 °C)–exsolution cycles.
Inverse Opal-Like, Ca3Al2O6-Stabilized, CaO-Based CO2 Sorbent: Stabilization of a Highly Porous Structure To Improve Its Cyclic CO2 Uptake
Kim, Sung Min; Armutlulu, Andac; Kierzkowska, Agnieszka M.; et al. (2019)
ACS Applied Energy Materials
Effective CO2 sorbents were manufactured utilizing inverse opal (IO)-like, CaO-based structures enabled by carbon nanosphere templates. To stabilize the structures against sintering, Ca3Al2O6 was incorporated via three different routes (i.e., one-pot synthesis, impregnation, and atomic layer deposition (ALD)). The sorbents realized through one-pot and ALD-assisted synthesis methods exhibited a significantly enhanced CO2 uptake when compared to the benchmark limestone and the sorbent realized by postsynthesis impregnation. The differences in the performances of the materials were rationalized by relating the textural properties of the material to the CO2 uptake in the kinetically controlled and diffusion-limited carbonation stages. We observe that both the kinetically and diffusion-limited carbonation stages are critically linked to the volume in pores with dpore < 100 nm and the surface area of the material.
Bifunctional core-shell architecture allows stable H2 production utilizing CH4 and CO2 in a catalytic chemical looping process
Hosseini, Davood; Abdala, Paula Macarena; Donat, Felix; et al. (2019)
Applied Catalysis B: Environmental
We report on the development of a bifunctional catalyst (Pt) - oxygen carrier (Fe2O3) that integrates the dry reforming of methane (DRM) into the chemical looping-based production of hydrogen. The material exhibits a high and stable methane conversion (˜ 80%) and hydrogen yield (10.8 mmol/g catalyst-oxygen carrier) with only a small quantity of impurities (CO, CO2 <2 ppm). The structural changes of the material are followed by operando X-ray powder diffraction and X-ray absorption spectroscopy coupled with gas chromatography. Insight into the evolution of the size of the Pt nanoparticles and their interaction with CeO2 are probed by transmission electron microscopy and X-ray absorption fine structure analysis. Under DRM conditions, the Pt nanoparticles grow in size, however, their re-dispersion on the CeO2 support (via PtOx-support interaction) during air oxidation recovers their activity in the consecutive cycle.

Publications 1 - 10 of 12

Sung Min Kim

Last Name

First Name

ORCID

Organisational unit

Filters

Search Results