Raman and Infrared Spectroscopic Studies on Li&lt;sub&gt;4&lt;/sub&gt;RuH&lt;sub&gt;6&lt;/sub&gt; Combined with First-Principles Calculations

Sato, Toyoto; Takagi, Shigeyuki; Matsuo, Motoaki; Aoki, Katsutoshi; Deledda, Stefano; Hauback, Bjørn C.; Orimo, Shin Ichi

doi:10.2320/matertrans.mg201403

Cited by 21 publications

(11 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To get more understanding of the H 2 desorption event, the temperature-dependent solid-phase structure change of the Pd–10LiH-BM sample in an Ar flow was monitored by using the synchrotron in situ PXRD technique. As shown in Figure b, Pd is the only detected crystalline phase at room temperature, while LiH is likely in an amorphous state after ball-milling treatment . Interestingly, two kinds of ternary lithium palladium hydrides, i.e., LiPdH 0.7 and Li 2 PdH 2 , were formed above 85 and 135 °C, respectively.…”

Section: Resultsmentioning

confidence: 92%

“…Interestingly, two kinds of ternary lithium palladium hydrides, i.e., LiPdH 0.7 and Li 2 PdH 2 , were formed above 85 and 135 °C, respectively. Some ternary lithium transition metal hydrides have been reported in the literature, , most of which, including Li 4 FeH 6 , Li 4 RuH 6 , etc., are normally prepared under high pressures and high temperatures. ,, The formation of ternary lithium palladium hydrides (hereafter denoted as [Li–Pd–H]), however, occurs under much milder conditions, indicating the the reactions of Pd and LiH forming [Li–Pd–H] (reaction ) are both thermodynamically and kinetically feasible. With further increasing temperature, however, Li 2 PdH 2 and LiPdH 0.7 disappeared above 240 and 330 °C, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…As shown in Figure 1b, Pd is the only detected crystalline phase at room temperature, while LiH is likely in an amorphous state after ball-milling treatment. 24 Interestingly, two kinds of ternary lithium palladium hydrides, i.e., LiPdH 0.7 and Li 2 PdH 2 , were formed above 85 and 135 °C, respectively. Some ternary lithium transition metal hydrides have been reported in the literature, 25,26 most of which, including Li 4 FeH 6 , Li 4 RuH 6 , etc., are normally prepared under high pressures and high temperatures.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Lithium Palladium Hydride Promotes Chemical Looping Ammonia Synthesis Mediated by Lithium Imide and Hydride

et al. 2021

View full text Add to dashboard Cite

Palladium (Pd) has long been known to be inactive for dinitrogen activation and hence has received little attention for ammonia synthesis. Herein, we report that the reactivity of Pd is changed when reacting with lithium hydride (LiH) forming a series of lithium palladium hydrides such as LiPdH0.7 and Li2PdH2 (denoted as [Li–Pd–H]). LiPdH0.7 promotes N2 fixation by LiH forming Li2NH and LiPd, and the subsequent hydrogenation of Li2NH and LiPd leads to ammonia and regeneration of LiH and [Li–Pd–H]. Based on these experimental results, an ammonia loop mediated by a [Li–Pd–H]–LiH and LiPd–Li2NH composite pair is proposed and demonstrated. An ammonia production rate of 693 μmolNH3 g–1 h–1 was achieved at 300 °C and 1 bar, which is ca. 7 times that of the neat LiH/Li2NH pair at 350 °C and 1 bar and 2 times that of the thermocatalytic process catalyzed by Ru/MgO at 300 °C and 10 bar.

show abstract

Section: Resultsmentioning

confidence: 92%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Lithium Palladium Hydride Promotes Chemical Looping Ammonia Synthesis Mediated by Lithium Imide and Hydride

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The newly formed Fe–O, Ni–O, and Co–O bonds suggest the generation of Fe-OH * , Ni-OH * , and Co-OH * intermediates, which originate from the cleavage of H 2 O molecules. Interestingly, two sharp Raman peaks that emerged at 2069 and 2092 cm −1 correspond to the Ru-H bonds, strongly suggesting the formation of Ru-H * intermediates 38 , 39 . With increasing applied potentials ranging from 60 to 180 mV, the intensities of all characteristic Raman peaks continuously increased, suggesting enhanced HER activity.…”

Section: Resultsmentioning

confidence: 99%

Unraveling the electronegativity-dominated intermediate adsorption on high-entropy alloy electrocatalysts

et al. 2022

View full text Add to dashboard Cite

High-entropy alloys have received considerable attention in the field of catalysis due to their exceptional properties. However, few studies hitherto focus on the origin of their outstanding performance and the accurate identification of active centers. Herein, we report a conceptual and experimental approach to overcome the limitations of single-element catalysts by designing a FeCoNiXRu (X: Cu, Cr, and Mn) High-entropy alloys system with various active sites that have different adsorption capacities for multiple intermediates. The electronegativity differences between mixed elements in HEA induce significant charge redistribution and create highly active Co and Ru sites with optimized energy barriers for simultaneously stabilizing OH* and H* intermediates, which greatly enhances the efficiency of water dissociation in alkaline conditions. This work provides an in-depth understanding of the interactions between specific active sites and intermediates, which opens up a fascinating direction for breaking scaling relation issues for multistep reactions.

show abstract

“…Further examples of the flexible coordination of the ruthenium hydride anions [63] are the formation of Na 4-RuH 6 and Li 4 RuH 6 . Unfortunately, no thermodynamic studies have been conducted on these materials, although further studies of Li 4 RuH 6 have been carried out by means of first-principles calculations and vibrational spectroscopy [69]. The lack of physical information on these compounds (and the following materials) is likely due to the cost of the raw materials which inhibits not only technological applications but also the ability to perform accurate thermodynamic measurements (due to the quantities of materials required).…”

Section: Sodium-based Complex Transition Metal Hydridesmentioning

confidence: 99%

Sodium-based hydrides for thermal energy applications

2016

View full text Add to dashboard Cite

Concentrating solar-thermal power (CSP) with thermal energy storage (TES) represents an attractive alternative to conventional fossil fuels for base-load power generation. Sodium alanate (NaAlH 4 ) is a well-known sodium-based complex metal hydride but, more recently, high-temperature sodium-based complex metal hydrides have been considered for TES. This review considers the current state of the art for NaH, NaMgH 3-x F x , Na-based transition metal hydrides, NaBH 4 and Na 3 AlH 6 for TES and heat pumping applications. These metal hydrides have a number of advantages over other classes of heat storage materials such as high thermal energy storage capacity, low volume, relatively low cost and a wide range of operating temperatures (100°C to more than 650°C). Potential safety issues associated with the use of high-temperature sodium-based hydrides are also addressed.

show abstract

Raman and Infrared Spectroscopic Studies on Li<sub>4</sub>RuH<sub>6</sub> Combined with First-Principles Calculations

Abstract: We have studied the vibrational properties of Li 4

Cited by 21 publications

References 26 publications

Lithium Palladium Hydride Promotes Chemical Looping Ammonia Synthesis Mediated by Lithium Imide and Hydride

Lithium Palladium Hydride Promotes Chemical Looping Ammonia Synthesis Mediated by Lithium Imide and Hydride

Unraveling the electronegativity-dominated intermediate adsorption on high-entropy alloy electrocatalysts

Sodium-based hydrides for thermal energy applications

Contact Info

Product

Resources

About