Strontium Manganese Oxide Getter for Capturing Airborne Cr and S Contaminants in High-Temperature Electrochemical Systems

Hong, Jae Won; Aphale, Ashish; Heo, Su Jeong; Hu, Boxun; Reisert, Michael; Belko, Seraphim; Singh, Prabhakar

doi:10.1021/acsami.9b09677

Cited by 12 publications

(9 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The LSCF particle surface has numerous nano-bumps indicative of Sr exsolution (Figure 5A), which was not initially present (Figure 6B). The nano-bumps are likely to be sulfur compounds such as SrSO 4 , based on previous research (Hong et al, 2019). Correspondingly, as can be seen in Figure 5B, the EDS spectrum from the LSCF particle with the surface nanoparticles (Region 2), shows a higher sulfur concentration than that from the LSCF particle core (Region 1).…”

Section: Structural Modification Of Lscf and Lsm In Cyclic Conditionssupporting

confidence: 56%

“…The LSM particles appear to have smooth surfaces with no evidence of Sr exsolution and SrSO 4 formation (Figure 8A). It should be noted that in our previous study (Hong et al, 2019), an LSM|YSZ cell, exposed to 4 ppm SO 2 for 120 h but without subsequent exposure to air flow, has sulfur-enriched nanoparticles (regarded as SrSO 4 ) protruding on the surface. It is thus indicated that, in the subsequent air flow, the sulfur physi/chemisorbed on the LSM surface is released while the strontium is partially dissolved back into LSM.…”

Section: Structural Modification Of Lscf and Lsm In Cyclic Conditionsmentioning

confidence: 86%

See 1 more Smart Citation

Sulfur Poisoning and Performance Recovery of SOFC Air Electrodes

Hong¹,

Anisur²,

Heo³

et al. 2021

Front. Energy Res.

Self Cite

View full text Add to dashboard Cite

The sulfur poisoning and performance recovery of the state-of-the-art SOFC cathodes (La0.80Sr0.20)0.95MnO3±δ (LSM) and (La0.60Sr0.40)0.95Co0.20Fe0.80O3–δ (LSCF), have been studied. Electrochemical impedance spectroscopy measurements of LSCF|GDC and LSM|YSZ half-cells are carried out in alternating atmospheres of air and SO2–air at 700°C for hundreds of hours. In the presence of SO2, the electrochemical performance of both the cells decays with ohmic and non-ohmic losses, owing to the absorption and chemical interaction of SO2 with the electrodes. In LSCF, the SrO segregated on the surface tends to absorb and react with SO2, forming SrSO4 followed by the exsolution of Co-Fe. As for LSM, SO2 is absorbed onto the Sr-rich areas of LSM, including the active reaction sites near the TPBs, leading to Sr exsolution and SrSO4 formation, leaving a Sr-deficient LSM. During the subsequent exposure to air, the performance of the sulfur-contaminated LSM is almost restored. The LSM particles, exposed to alternating atmospheres of air and SO2-air during the electrochemical tests, show a relatively clean surface with sparsely distributed SrSO4 particles, indicating a high stability against sulfur poisoning. It is suggested that the loosely adsorbed SO2 at the TPBs is readily swept away by the SO2-free air flow, recovering its ORR activity, whereas the Sr-deficient LSM due to Sr-exsolution stays modified, contributing to the incomplete performance restoration. Unlike the case of LSM, the performance of the sulfur-poisoned LSCF partially recovers during the subsequent exposure to air. Correspondingly, the LSCF particles have a modified morphology covered with numerous nanoparticles, mostly SrSO4, showing the irreversible aspect of the sulfur poisoning. The morphology modification is not concentrated near the electrode/electrolyte interface but over the entire cathode, indicating that the degree of recovery from sulfur poisoning is closely related to the presence of SrO and chemical activity of Sr in the electrodes at the solid-gas interface. These results also show the potential application of LSM for a sulfur sensor available in high-temperature harsh conditions.

show abstract

Section: Structural Modification Of Lscf and Lsm In Cyclic Conditionssupporting

confidence: 56%

Section: Structural Modification Of Lscf and Lsm In Cyclic Conditionsmentioning

confidence: 86%

Sulfur Poisoning and Performance Recovery of SOFC Air Electrodes

Hong¹,

Anisur²,

Heo³

et al. 2021

Front. Energy Res.

Self Cite

View full text Add to dashboard Cite

show abstract

“…For instance, SrCO 3 nanowhiskers were found to grow from Sr 4 Mn 3 O 10 in humid environment (see Supplementary Fig. S4 online), which have potential applications as Cr/S getters 43 in high-temperature electrochemical systems. While water molecules are considered contributors to the directional growth, the role of water molecules in Sr carbonation is rarely studied.…”

Section: Resultsmentioning

confidence: 99%

Water mediated growth of oriented single crystalline SrCO3 nanorod arrays on strontium compounds

Hong

Heo

Singh

2021

Sci Rep

Self Cite

View full text Add to dashboard Cite

Morphology-controlled strontianite nanostructures have attracted interest in various fields, such as electrocatalyst and photocatalysts. Basic additives in aqueous strontium solutions is commonly used in controlling strontianite nanostructures. Here, we show that trace water also serves an important role in forming and structuring vertically oriented strontianite nanorod arrays on strontium compounds. Using in situ Raman spectroscopy, we monitored the structural evolution from hydrated strontium to strontianite nanorods, demonstrating the epitaxial growth by vapor–liquid–solid mechanism. Water molecules cause not only the exsolution of Sr liquid droplets on the surface but also the uptake of airborne CO2 followed by its ionization to CO32−. The existence of intermediate SrHO+–OCO22− phase indicates the interaction of CO32− with SrOH+ in Sr(OH)x(H2O)y cluster to orient strontianite crystals. X-ray diffraction simulation and transmission electron microscopy identify the preferred-orientation plane of the 1D nanostructures as the (002) plane, i.e., the growth along the c-axis. The anisotropic growth habit is found to be affected by the kinetics of carbonation. This study paves the way for designing and developing 1D architecture of alkaline earth metal carbonates by a simple method without external additives at room temperature.

show abstract

“…Borosilicate glass sealants have also been modified with B-stabilizing dopants to form borates, but completely mitigating B volatility remains a challenge (38,39). Recently, sacrificial and cost-effective 'getters' have been proposed and demonstrated as a method to capturing SO2 and Cr vapor contaminants with before reaching electrochemically sensitive components (40,41,42). Based on basic alkaline-earth metals, the getter's affinity for acidic CO2(g), SO2(g), Si(OH)4(g), H3BO3(g) and CrO2(OH)2(g) makes them capable of scrubbing contaminated air, preserving solid oxide cell performance (42,43).…”

Section: Introductionmentioning

confidence: 99%

Multi-Contaminant Getter for Trace Airborne Contaminant Capture in Elevated Temperature Electrochemical Systems

Belko¹,

Dubey²,

Lee³

et al. 2023

ECS Trans.

View full text Add to dashboard Cite

Electrode poisoning in high temperature electrochemical systems from trace levels of airborne contaminants remains a critical issue, contributing to long-term irreversible performance degradation. The intrinsic and extrinsic presence of gas phase Cr, Si, B, and SOx, species in air have been reported to form detrimental secondary compounds and microstructural changes at the electrode/electrolyte interface, consuming electrochemically active sites. Herein, a novel contaminant capture method is reported that uses low-cost getter materials based on alkaline-earth metals. The getters, in benchtop transpiration tests, demonstrated the desired ability to form thermodynamically stable reaction products and reducing the gaseous contaminant partial pressures by several orders of magnitude. Consumption of the contaminants in the getter preserves the performance of solid oxide cells. The presented results have demonstrated the feasibility of the use of getter materials under operating conditions typical to elevated-temperature electrochemical systems.

show abstract

Strontium Manganese Oxide Getter for Capturing Airborne Cr and S Contaminants in High-Temperature Electrochemical Systems

Cited by 12 publications

References 55 publications

Sulfur Poisoning and Performance Recovery of SOFC Air Electrodes

Sulfur Poisoning and Performance Recovery of SOFC Air Electrodes

Water mediated growth of oriented single crystalline SrCO3 nanorod arrays on strontium compounds

Multi-Contaminant Getter for Trace Airborne Contaminant Capture in Elevated Temperature Electrochemical Systems

Contact Info

Product

Resources

About