Conformal Electrocatalytic Surface Nanoionics for Accelerating High-Temperature Electrochemical Reactions in Solid Oxide Fuel Cells

Abstract

Additive implantation of electrocatalysts onto the internal surface of porous cathodes holds great promise to accelerate the electrochemical reactions within solid oxide fuel cells (SOFCs). Here we utilize atomic layer deposition (ALD) to apply dual catalysts with (Mn0.8Co0.2)3O4 and a minute amount of Pt on the cathode consisting of lanthanum strontium manganite (LSM) and yttria-stabilized zirconia (YSZ). Coating this material with optimum ALD layer thickness resulted in a 53% reduction of polarization resistance and a 350% SOFC peak power density enhancement at 750 °C. During the electrochemical operations, the dual catalysts interact synergistically and evolve into superjacent conformal electrocatalytic (Mn0.8Co0.2)3O4 nanoionics with high-density grain boundaries and subjacent discrete nano Pt particles evenly distributed on both the LSM and YSZ. The configuration consequently extends the active electrochemical reaction sites to the entire internal surface of the cathode. For the first time in the field of SOFCs, the present work demonstrates the formation of the electrocatalytic surface nanoionics and its resultant accelerated mass and charge transfer to dramatically boost the cell performance.

Noble‐Metal‐Assisted Fast Interfacial Oxygen Migration with Topotactic Phase Transition in Perovskite Oxides

“…[ 42 ] Nanostructured Pt catalysts by atomic‐layer deposition [ 43 ] can improve SOFC performance at low temperatures owing to a high triple‐phase‐boundary density [ 44 ] and electrocatalytic surface nanoionics. [ 45 ] In YSZ/Pt electrode of SOFCs, the fully mixed cermet interlayers provide thermal stability of the Pt particles and large density of catalytically active sites. [ 46 ] Our work elucidates the effect of ultrathin noble metal layers in facilitating O 2− migration of perovskite oxides, and we speculate the activation effect can be further enhanced by maximizing the contact area of metal/oxide interface in nanoparticle or nanoporous configuration.…”

Nanoscale interface engineering for solid oxide fuel cells using atomic layer deposition

“…In contrast, ALD offers the advantage of reproducibly introducing metal nanocatalysts with high uniformity even on complicated structures and easily depositing composite oxides with diverse compositions. [77][78][79][80][81][82][83][84][85][86] Recently, Tsampas reported an example of successful electrode activity enhancement using ALD by uniformly coating Pt nanocatalysts onto an LSCM electrode (Fig. 8a).…”

Recent Advances in Materials Design Using Atomic Layer Deposition for Energy Applications

“…[ 215 ] However, the electrochemical performance cathode drops at low operating temperature due to poor oxygen reduction reaction (ORR). Surface modification of thermally stable metal oxides such as doped ZrO 2 , [ 216 ] CeO x , [ 217 ] Al 2 O 3 , [ 218 ] TiO x , [ 219 ] and SnO x , [ 220 ] perovskite‐based cathodes materials ((Mn 0.8 Co 0.2 ) 3 O 4 , [ 221 ] Pr 6 O 11 [ 222 ] ), and metals (pure and alloys) (Pt, [ 223 ] Ru, [ 224 ] Pd, [ 225 ] Ni, [ 226 ] Al, [ 227 ] PtRu, [ 228 ] NiPd, [ 225 ] NiRu [ 229 ] ) have been engineered via the ALD technique. These nanostructured coatings/electrode materials are proven to be effective in stabilizing the catalyst surface without sacrificing the surface activity.…”

“…The catalyst lowered the polarization resistance of cathode by up to 53% and a 350% SOFC peak power density enhancement is achieved at 750 °C. [ 221 ] Electrode surface poisoning is another major reason of SOFC performance degradation. [ 215a ] To enhance the durability of electrodes, Dogdibegovic et al.…”