A-site order–disorder in the NdBaMn₂O_5+δ SOFC electrode material monitored in situ by neutron diffraction under hydrogen flow

Abstract

Phase change of Nd0.5Ba0.5MnO3−δ to the electrode material, NdBaMn2O5+δ, occurs under hydrogen atmosphere at T ∼ 800 °C.

In situ exsolution of Ni particles on the PrBaMn2O5 SOFC electrode material monitored by high temperature neutron powder diffraction under hydrogen

“…Conventional SOFCs employ Ni-based cermet anodes which display high electronic conductivity, excellent electrocatalytic activity for fuel oxidation and good compatibility with zirconia-or ceria-based electrolytes but suffers from serious drawbacks such as volume change on redox cycling and Ni coarsening during operation as well as carbon build-up (coking) and sulfur contamination from hydrocarbon fuels [4][5][6] . Several materials have been investigated as alternatives to Ni-based cermet anode to overcome coking and impurity poisoning issues and A-site layered double perovskites (LDP) LnBaMn 2 O 5+δ (Ln = Pr, Nd) have received particular attention owing to their mixed ionic and electronic conductivity (MIEC), redox stability, superior resistance to coking and sulfur poisoning and good mechanical compatibility with common electrolytes but their (electro)catalytic activity for fuel oxidation is insufficient for practical applications [7][8][9][10][11] .…”

“…A few years ago, we published the first real time in situ high temperature neutron powder diffraction (NPD) of the layered double perovskite (LDP) manganite, NdBaMn 2 O 5+δ , under hydrogen atmosphere 8,9 . In the work reported here, we target the synthesis of Ni-doped A-site deficient LDP manganite, (LnBa) 1-x/2 Mn 2-x Ni x O 5+δ with Ln = Pr and x = 0.05.…”

Exsolution of Ni Nanoparticles from A-Site-Deficient Layered Double Perovskites for Dry Reforming of Methane and as an Anode Material for a Solid Oxide Fuel Cell

“…Interesting alternative materials to Ni/YSZ cermet anodes are mixed ionic and electronic conducting (MIEC) oxides among which the A-site layered ordered perovskites, LnBaMn 2 O 5+δ with Ln = Pr, Nd, have been identified as potential candidates because of their redox stability and reduced sensitivity to sulfur-containing fuel impurities. [4][5][6] However, their electrochemical performance under hydrogen and hydrocarbon fuels is poor. 7 The electrochemical performance of ceramic anodes can be improved by adding a small amount of electrocatalyst nanoparticles (NPs) by impregnating the MIEC oxide with a metallic salt or a suspension of metallic nanoparticles.…”

“…In addition, Ni/YSZ exhibits unsatisfactory performance during operation with methane due to carbon deposition from cracking (CH 4 = C + 2H 2 ) and sulfur poisoning blocking the catalyst sites. Alternative anode materials to Ni/YSZk cermet are mixed ionic and electronic conducting (MIEC) oxides, among which the A-site layered ordered perovskites, LnBaMn 2 O 5+δ with Ln = Pr, Nd, have been identified as potential candidates because of their redox stability and reduced sensitivity to sulfur-containing fuel impurities. − However, their electrochemical performance under hydrogen and hydrocarbon fuels is poor . The electrochemical performance of ceramic anodes can be improved by adding a small amount of electrocatalyst nanoparticles (NPs) by impregnating the MIEC oxide with a metallic salt or a suspension of metallic nanoparticles. − However, this technique generally results in weak bonding between the NPs and the support that often leads to coarsening of the Ni catalyst particles during cell processing or cell tests .…”

Investigation of Structural and Thermal Evolution in Novel Layered Perovskite NdSrMn2O5+δ via Neutron Powder Diffraction and Thermogravimetric Analysis

“…Some layeredtype perovskites used as electrodes in SOFCs [14][15][16][17][18] fueled through hydrogen or other syngas [19][20][21][22] have also shown promising results. e structural distortion is our core consideration as it affects the physical and electrochemical properties of the perovskite-type oxides [23][24][25]. Neutron diffraction is a robust technique that can determine complex crystal structure, oxygen stoichiometry, and oxygen vacancy ordering.…”