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Title: La and Al co-doped CaMnO 3 perovskite oxides: From interplay of surface properties to anion exchange membrane fuel cell performance

Abstract

This work reports the first account of perovskite oxide and carbon composite oxygen reduction reaction (ORR) catalysts integrated into anion exchange membrane fuel cells (AEMFCs). Perovskite oxides with a theoretical stoichiometry of Ca 0.9La 0.1Al 0.1Mn 0.9O 3-δ are synthesized by an aerogel method and calcined at various temperatures, resulting in a set of materials with varied surface chemistry and surface area. Material composition is evaluated by X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The perovskite oxide calcined at 800 degrees C shows the importance of balance between surface area, purity of the perovskite phase, and surface composition, resulting in the highest ORR mass activity when evaluated in rotating disk electrodes. Integration of this catalyst into AEMFCs reveals that the best AEMFC performance is obtained when using composites with 30:70 perovskite oxide:carbon composition. Doubling the loading leads to an increase in the power density from 30 to 76 mW cm -2. The AEMFC prepared with a composite based on perovskite oxide and N-carbon achieves a power density of 44 mW cm -2, demonstrating an ~50% increase when compared to the highest performing composite with undoped carbon at the same loading.

Authors:
 [1];  [2];  [2]; ORCiD logo [1];  [1];  [3];  [1];  [1]; ORCiD logo [1]
  1. Colorado School of Mines, Golden, CO (United States)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States); Colorado School of Mines, Golden, CO (United States)
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1412828
Report Number(s):
NREL/JA-5900-70170
Journal ID: ISSN 0378-7753; TRN: US1800369
Grant/Contract Number:
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Power Sources
Additional Journal Information:
Journal Volume: 375; Journal Issue: C; Journal ID: ISSN 0378-7753
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AEMFC; oxygen reduction reaction; perovskite oxide electrocatalyst; XPS; STEM-EDS; N-functionalized carbon

Citation Formats

Dzara, Michael J., Christ, Jason M., Joghee, Prabhuram, Ngo, Chilan, Cadigan, Christopher A., Bender, Guido, Richards, Ryan M., O'Hayre, Ryan, and Pylypenko, Svitlana. La and Al co-doped CaMnO3 perovskite oxides: From interplay of surface properties to anion exchange membrane fuel cell performance. United States: N. p., 2017. Web. doi:10.1016/j.jpowsour.2017.08.071.
Dzara, Michael J., Christ, Jason M., Joghee, Prabhuram, Ngo, Chilan, Cadigan, Christopher A., Bender, Guido, Richards, Ryan M., O'Hayre, Ryan, & Pylypenko, Svitlana. La and Al co-doped CaMnO3 perovskite oxides: From interplay of surface properties to anion exchange membrane fuel cell performance. United States. doi:10.1016/j.jpowsour.2017.08.071.
Dzara, Michael J., Christ, Jason M., Joghee, Prabhuram, Ngo, Chilan, Cadigan, Christopher A., Bender, Guido, Richards, Ryan M., O'Hayre, Ryan, and Pylypenko, Svitlana. Fri . "La and Al co-doped CaMnO3 perovskite oxides: From interplay of surface properties to anion exchange membrane fuel cell performance". United States. doi:10.1016/j.jpowsour.2017.08.071.
@article{osti_1412828,
title = {La and Al co-doped CaMnO3 perovskite oxides: From interplay of surface properties to anion exchange membrane fuel cell performance},
author = {Dzara, Michael J. and Christ, Jason M. and Joghee, Prabhuram and Ngo, Chilan and Cadigan, Christopher A. and Bender, Guido and Richards, Ryan M. and O'Hayre, Ryan and Pylypenko, Svitlana},
abstractNote = {This work reports the first account of perovskite oxide and carbon composite oxygen reduction reaction (ORR) catalysts integrated into anion exchange membrane fuel cells (AEMFCs). Perovskite oxides with a theoretical stoichiometry of Ca0.9La0.1Al0.1Mn0.9O3-δ are synthesized by an aerogel method and calcined at various temperatures, resulting in a set of materials with varied surface chemistry and surface area. Material composition is evaluated by X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The perovskite oxide calcined at 800 degrees C shows the importance of balance between surface area, purity of the perovskite phase, and surface composition, resulting in the highest ORR mass activity when evaluated in rotating disk electrodes. Integration of this catalyst into AEMFCs reveals that the best AEMFC performance is obtained when using composites with 30:70 perovskite oxide:carbon composition. Doubling the loading leads to an increase in the power density from 30 to 76 mW cm-2. The AEMFC prepared with a composite based on perovskite oxide and N-carbon achieves a power density of 44 mW cm-2, demonstrating an ~50% increase when compared to the highest performing composite with undoped carbon at the same loading.},
doi = {10.1016/j.jpowsour.2017.08.071},
journal = {Journal of Power Sources},
number = C,
volume = 375,
place = {United States},
year = {Fri Sep 01 00:00:00 EDT 2017},
month = {Fri Sep 01 00:00:00 EDT 2017}
}

Journal Article:
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  • Density functional theory (DFT) based investigation of two parameters of prime interest -- oxygen vacancy and surface terminations along (100) and (110) planes -- has been conducted for La (1-x)Sr xFe(1-y)Co yO (3-more » $$\delta$$) perovskite oxides in view of their application towards thermochemical carbon dioxide conversion reactions. The bulk oxygen vacancy formation energies for these mixed perovskite oxides are found to increase with increasing lanthanum and iron contents in the 'A' site and 'B' site, respectively. Surface terminations along (100) and (110) crystal planes are studied to probe their stability and their capabilities to accommodate surface oxygen vacancies. Amongst the various terminations, the oxygen-rich (110) surface and strontium-rich (100) surface are the most stable, while transition metal-rich terminations along (100) revealed preference towards the production of oxygen vacancies. The carbon dioxide adsorption strength, a key descriptor for CO 2 conversion reactions, is found to increase on oxygen vacant surfaces thus establishing the importance of oxygen vacancies in CO 2 conversion reactions. Amongst all the surface terminations, the lanthanum-oxygen terminated surface exhibited the strongest CO 2 adsorption strength. Finally, the theoretical prediction of the oxygen vacancy trends and the stability of the samples were corroborated by the temperature-programmed reduction and oxidation reactions and in situ XRD crystallography.« less
  • Oxygen desorption from La{sub 1{minus}x}Sr{sub x}Co{sub 1{minus}y}Fe{sub y}O{sub 3} perovskite-type oxides below 850{degree}C was examined by a temperature-programmed desorption (TPD) technique. The catalytic activities of the oxides for the combustion of n-butane and methane as well as H{sub 2}O{sub 2} decomposition in an alkaline solution were also measured and were discussed in relation to oxygen sorption properties. The amount of oxygen desorbed increased with increasing Sr content at a fixed B-site composition, for which an increase in the number of oxide ion vacancies with x was responsible. On the other hand, the total amount of oxygen desorbed was hardly affectedmore » by B-site composition, but partial substitution of Fe for Co enhanced desorption and sorption of oxygen particularly in the low-temperature region. Substitution of Sr for La as well as of Fe for Co was found to promote catalytic activity, though the activity changed with oxide composition in a manner dependent on the kind of reactant. For n-butane combustion over La{sub 1{minus}x}Sr{sub x}Co{sub 0.4}Fe{sub 0.6}O{sub 3}, maximum activity was obtained at x = 0.2. La{sub 0.2}Sr{sub 0.8}Co{sub 1{minus}y}Fe{sub y}O{sub 3} activity was highest at y = 0.4 for n-butane combustion, while it was independent of y for methane combustion. For H{sub 2}O{sub 2} decomposition in an alkaline solution, on the other hand, La{sub 1{minus}x}Sr{sub x}Co{sub 0.4}Fe{sub 0.6}O{sub 3} and La{sub 1{minus}x}Sr{sub x}CoO{sub 3} activities increased monotonically with an increase in x, and the former oxides were more active than the latter. These variations in catalytic activities with oxide composition were well accounted for by the oxygen sorption properties revealed by TPD.« less
  • The adsorption of CO on LnCoO/sub 3-chi/(Ln=La,Sm) was studied by temperature programmed desorption (TPD) method. At least two different sites were indicated by two CO TPD peak in both cases. The peak temperatures were 803 {Kappa}(I) and > 933 {Kappa}(II) for LaCoO/sub 3-chi/(chi-0.77), 823 {Kappa}(I) and >923 {Kappa}(II) for SmCoO/sub 3-chi/(chi=0.51) , respectively. The activation energies of desorption for CO(I) were 58 kJmol/sup -1/ for LaCoO/sub 3-chi/ and 74 kJmo1/sup -1/ for SmCoO/sub 3-chi/. These values were close to the dissociation energy between Co and bridged CO of Co/sub 2/(CO)/sub 8/. On the contrary, the desorption of CO/sub 2/ wasmore » observed, together with the desorption of CO, after the adsorption of CO on the reduced samples. The desorption of CO/sub 2/ was affected by the adsorbed partial pressure of CO and the adsorbed temperature. Thus, it is considered that the formation of CO/sub 2/ is due to the disproportionation reaction of adsorbed CO on LnCoO/sub 3-chi/; 2CO {yields} C + CO/sub 2/.« less
  • LaFeO{sub 3}, LaNiO{sub 3} and substituted LaFe{sub 1-y}Ni{sub y}O{sub 3} (y=0.1, 0.2 and 0.3) perovskites were synthesized by the citrate method and used in the catalytic combustion of ethanol and acetyl acetate. Chemical composition was determined by atomic absorption spectrometry (AAS) and specific areas from nitrogen adsorption isotherms. Structural details and surface properties were evaluated by temperature-programmed reduction (TPR), infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), temperature-programmed desorption of oxygen (O{sub 2}-TPD) and photoelectron spectroscopy (XPS). Characterization data revealed that total insertion of nickel in the LaFeO{sub 3} takes place for substitution y=0.1. However, NiO segregation occurs to some extent,more » specifically at higher substitutions (y>0.1). The catalytic performance of these perovskites was evaluated in the combustion of acetyl acetate and ethanol. Among these molecules, ethanol exhibited the lowest ignition temperature, and the catalytic activity expressed as intrinsic activity (mol m{sup -2} h{sup -1}) was found to increase substantially with the nickel substitution. These results can be explained in terms of the cooperative effect of a LaFe{sub 1-y}Ni{sub y}O{sub 3} and NiO phases, whose relative concentration determines the oxygen activation capability and hence their reactivity. - Graphical abstract: LaFeO{sub 3}, LaNiO{sub 3} and substituted LaFe{sub 1-y}Ni{sub y}O{sub 3} (y=0.1, 0.2 and 0.3) perovskite-type oxides have been investigated as catalysts in the total combustion of ethanol and acetylacetate. The characterization indicate variation in specific surface area, crystal structure, reducibility and surface composition. The catalytic activity expressed as intrinsic activity (mol m{sup -2} h{sup -1}) increases with nickel substitution. A synergy between Ni{sup 3+} and Fe{sup 3+} cations at the B position of the LaFe{sub 1-y}Ni{sub y}O{sub 3} perovskite for VOCs combustion was observed.« less
  • Thermal solid-solid interactions in cobalt treated MoO{sub 3}/Al{sub 2}O{sub 3} system were investigated using X-ray powder diffraction. The solids were prepared by wet impregnation method using Al(OH){sub 3}, ammonium molybdate and cobalt nitrate solutions, drying at 100 deg. C then calcination at 300, 500, 750 and 1000 deg. C. The amount of MoO{sub 3}, was fixed at 16.67 mol% and those of cobalt oxide were varied between 2.04 and 14.29 mol% Co{sub 3}O{sub 4}. Surface and catalytic properties of various solid samples precalcined at 300 and 500 deg. C were studied using nitrogen adsorption at -196 deg. C, conversion ofmore » isopropanol at 200-500 deg. C and decomposition of H{sub 2}O{sub 2} at 30-50 deg. C. The results obtained revealed that pure mixed solids precalcined at 300 deg. C consisted of AlOOH and MoO{sub 3} phases. Cobalt oxide-doped samples calcined at the same temperature consisted also of AlOOH, MoO{sub 3} and CoMoO{sub 4} compounds. The rise in calcination temperature to 500 deg. C resulted in complete conversion of AlOOH into very poorly crystalline {gamma}-Al{sub 2}O{sub 3}. The further increase in precalcination temperature to 750 deg. C led to the formation of Al{sub 2}(MoO{sub 4}){sub 3}, {kappa}-Al{sub 2}O{sub 3} besides CoMoO{sub 4} and un-reacted portion of Co{sub 3}O{sub 4} in the samples rich in cobalt oxide. Pure MoO{sub 3}/Al{sub 2}O{sub 3} preheated at 1000 deg. C composed of MoO{sub 3}-{alpha}Al{sub 2}O{sub 3} solid solution (acquired grey colour). The doped samples consisted of the same solid solution together with CoMoO{sub 4} and CoAl{sub 2}O{sub 4} compounds. The increase in calcination temperature of pure and variously doped solids from 300 to 500 deg. C increased their specific surface areas and total pore volume which suffered a drastic decrease upon heating at 750 deg. C. Doping the investigated system with small amounts of cobalt oxide (2.04 and 4 mol%) followed by heating at 300 and 500 deg. C increased its catalytic activity in H{sub 2}O{sub 2} decomposition. This increase, measured at 300 deg. C, attained 25.4- and 12.9-fold for the solids precalcined at 300 and 500 deg. C, respectively. The increase in the amount of dopant added above this limit decreased the catalytic activity which remained bigger than those of un-treated catalysts. On the other hand, the doping process decreased the catalytic activity of treated solids in isopropanol conversion especially the catalysts precalcined at 300 deg. C. This treatment modified the selectivities of treated solids towards dehydration and dehydrogenation of reacted alcohol. The activation energies of H{sub 2}O{sub 2} decomposition were determined for pure and variously doped solids. The results obtained were discussed in light of induced changes in chemical composition and surface properties of the investigated system due to doping with cobalt oxide.« less