CsH5(PO4)2/quartz fiber thin membranes for intermediate temperature fuel cells and electrochemical synthesis of ammonia

Qing, Geletu; Sukegawa, Kazuya; Kikuchi, Ryuji; Takagaki, Atsushi; Oyama, S. Ted

doi:10.1007/s10800-017-1082-1

Cited by 11 publications

(11 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The migration of the electrolyte can facilitate the formation of electrochemical reaction sites (triple‐phase boundaries of the electrolyte, the Pt/C catalyst, and the gas phase) [14,41] . However, excessive migration may lead to the performance degradation of the anode.…”

Section: Resultsmentioning

confidence: 99%

“…A group of pyrophosphates are also reported as proton conductors [10,11] . These solid acids have been widely investigated as electrolytes of fuel cells [9,12–16] . Consequently, application of the materials to electrolysis cells is considered promising [9] .…”

Section: Introductionmentioning

confidence: 99%

“…[10,11] These solid acids have been widely investigated as electrolytes of fuel cells. [9,[12][13][14][15][16] Consequently, application of the materials to electrolysis cells is considered promising. [9] The heat required for the electrolysis should be abundant because most of the global waste heat is of temperatures below 300°C.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Hydrogen Production by Steam Electrolysis in Solid Acid Electrolysis Cells

et al. 2020

Self Cite

View full text Add to dashboard Cite

Hydrogen production by steam electrolysis at intermediate temperatures has potential for both the high energy conversion efficiency and the flexible operability suitable for the utilization of renewable energy resources. Employment of proton-conducting solid acid electrolytes at around 200°C is considered promising but has rarely been investigated. Here, steam electrolysis was performed at 160-220°C using a solid acid electrolysis cell (SAEC) composed of a CsH 2 PO 4 /SiP 2 O 7 composite electrolyte and Pt/C electrodes. Hydrogen production was successfully demonstrated with Faraday efficiencies around 80 %. Key factors affecting the SAEC stability were investigated in detail for the first time. It was revealed that a certain part of the electrolyte migrated into the porous anode structure during the operation. The migrated electrolyte prevented the gas diffusion and flooded the Pt/C catalyst layer. It was also found that carbonaceous materials in the anode was oxidized, leading to the decrease in the number of electrochemically active sites. Based on the findings, Pt mesh was employed as an alternative anode. The SAEC with the Pt mesh anode showed superior stability, demonstrating the importance of the anode design. The present work provides a comprehensive view of the stability issues, which is essential for the development of durable and practical SAECs.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Hydrogen Production by Steam Electrolysis in Solid Acid Electrolysis Cells

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the past decade, there have been many studies on the direct electrochemical synthesis of ammonia at low temperature [3][4][5][6][7][8][9][10][11][12], intermediate temperature [13][14][15][16][17][18] and high temperature [19][20][21][22][23][24][25][26][27][28][29]. The reaction at the anode is water or hydrogen decomposition to form protons and oxygen and emitted electron (Eq.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical promotion of ammonia synthesis with proton-conducting solid oxide fuel cells

2019

Adv. Mater. Lett.

View full text Add to dashboard Cite

Direct electrochemical synthesis of ammonia was performed using proton-conducting solid oxide fuel cells. In this study, we investigated the effect of electrode potential on the reaction kinetics of ammonia formation with Fe-and Ru-based catalysts in detail. The cell configuration was Pt|BaCe0.9Y0.1O3 (BCY)|K-modified Fe or Ru-BCY. The ammonia formation rate of K-Ru was higher than that of K-Fe at the rest potential. However, the ammonia formation rate significantly increased by cathodic polarization for the Fe catalyst, and it showed a linear increase for the Ru catalyst, i.e., the ammonia formation rate for K-Fe significantly increased from the rest potential by several hundred times to-1.2V at 700C, but K-Ru showed only five times increase. The results suggest that the addition of K into Fe-BCY and cathodic polarization can improve the ammonia formation rate because of the promotion of bond dissociation of the N molecule on the Fe catalyst. The present work provides a hint for efficient ammonia formation and contribute to further development of ammonia electrochemical synthesis with proton-conducting solid oxide fuel cells.

show abstract

“…A commercial Pt/C sheet was employed as the anode because the Pt metal has catalytic activity for the dissociation of C-H bonds in ethane. 2 Regarding the utilization of a phosphate-based electrolyte at the intermediate temperatures, most studies have demonstrated its application in fuel cells [18][19][20] and very few studies have demonstrated its application in electrolysis cells for synthesizing variable chemicals such as ammonia. 21,22 No research has been reported on the electrochemical conversion of ethane to oxygenates at the intermediate temperatures so far.…”

mentioning

confidence: 99%