Robust solid oxide cells for alternate power generation and carbon conversion

Abstract

Solid oxide cells (SOCs) are potentially useful for versatile energy conversion and storage applications. This work demonstrates the feasibility of SOCs that are operated in alternate power generation and carbon conversion modes. SOCs with lanthanum strontium vanadate (LSV) hydrogen electrodes have been proved to be competent candidates for such applications. SOCs with LSV-based hydrogen electrodes exhibit salient catalytic activity in hydrogen and various simulated feedstocks, e.g. syngas, biogas, town gas, and coal gas. LSV electrodes seem to perform better in the electrolyser mode than in the fuel cell mode. LSV electrodes are unlikely to be coked by the deposited carbon when exposed to carbon-forming gases. Most interestingly, LSV undergoes continuous activation during the course of operation, instead of being poisoned, when exposed to gases containing 50 ppm H 2 S. LSV-based reversible SOCs under alternating electrolyser and fuel cell operations have been demonstrated with negligible performance degradation over 500 h.

Compromising Between Phase Stability and Electrical Performance: SrVO3–SrTiO3 Solid Solutions as Solid Oxide Fuel Cell Anode Components

“…Non‐negligible oxygen deficiency in the perovskite lattice ( δ =0.08–0.10) implies the contribution of oxygen‐ionic transport to electrical transport, which is favorable for electrochemical activity. SOFC anodes based on La‐substituted SrVO 3− δ have been reported to show stable performance in different fuels including hydrogen, syngas, and wet methane . No carbon deposition was detected during the tests in wet CH 4 .…”

“…[10][11][12][13][14] Non-negligible oxygen deficiency in the perovskite lattice (d = 0.08-0.10) [10,15] implies the contribution of oxygen-ionic transport to electricalt ransport, which is favorable for electrochemical activity.S OFC anodesb ased on La-substituted SrVO 3Àd have been reported to show stable performance in different fuels including hydrogen, syngas, and wet methane. [16][17][18][19][20][21][22][23][24] No carbon deposition was detectedd uring the tests in wet CH 4 . [22][23][24] Furthermore, Sr 1Àx La x VO 3Àd anodes have been demonstrated to exhibit excellent tolerance towards H 2 Si mpurities in af uel( up to concentrations as high as 5-10 vol %) [16][17][18][19][20] and even to promote its oxidationt oS O 2 .…”

“…[16][17][18][19][20][21][22][23][24] No carbon deposition was detectedd uring the tests in wet CH 4 . [22][23][24] Furthermore, Sr 1Àx La x VO 3Àd anodes have been demonstrated to exhibit excellent tolerance towards H 2 Si mpurities in af uel( up to concentrations as high as 5-10 vol %) [16][17][18][19][20] and even to promote its oxidationt oS O 2 . [16,17] The main limitations of SrVO 3Àd are instability under oxidizing conditions and high thermochemical expansion coefficient (TEC).…”

“…SOFC anodes based on La‐substituted SrVO 3− δ have been reported to show stable performance in different fuels including hydrogen, syngas, and wet methane . No carbon deposition was detected during the tests in wet CH 4 . Furthermore, Sr 1− x La x VO 3− δ anodes have been demonstrated to exhibit excellent tolerance towards H 2 S impurities in a fuel (up to concentrations as high as 5–10 vol %) and even to promote its oxidation to SO 2 …”

Solid Oxide Fuel Cell Anode Materials for Direct Hydrocarbon Utilization

“…[ 354 ] Combined experimental and theoretical studies depicted the electrochemical double layer, [ 355 ] double layer capacitance, [ 356 , 357 ] three phase boundaries, and electrochemically active zones of highly active LSV/YSZ interfaces. [ 358 ] La 0.6 Sr 0.4 VO 3 synthesized from citric route was able to achieve R p of 0.43 and 0.56 Ω cm 2 in pure H 2 and 70H 2 -30CO-50 ppm H 2 S, respectively, at 900 ° C. It is worth highlighting that LSV anodes underwent continuous improvement, rather than being poisoned, in H 2 S-laden coal gas and biogas up to 500 h. [ 359 ] Matching the chemical and thermal expansion of vanadate in a wide range of pO 2 is one of the approaches to mitigate the redox instability problem. There is 30% of volume change of the reversible phase transition between perovskite CaV 0.5 Mo 0.5 O 3 and scheelite CaV 0.5 Mo 0.5 O 3.…”