Enhancing Perovskite Electrocatalysis of Solid Oxide Cells Through Controlled Exsolution of Nanoparticles

Abstract

Perovskite oxides have received a great deal of attention as promising electrodes in both solid oxide fuel cells (SOFCs) and solid oxide electrolyzer cells (SOECs) because of their reasonable reactivity, impurity tolerance, and tunable properties. In particular, exploration is still required for improving perovskite electrodes, which normally suffer from slow kinetics in electrocatalysis. Experimental studies have led to the development of new classes of perovskites with advanced characteristics and electrode kinetics at technical levels. In parallel with those developments, achievements in theoretical and computational studies have led to substantial understanding, at the atomic level, of their physicochemical properties and electrocatalytic behaviors. Their chemical and structural flexibilities enable perovskites to accommodate most metallic elements without destroying their complex matrix structures, thereby delivering a pathway to engineer their catalytic properties. In this Minireview, recent advances in perovskite electrodes are introduced, and perovskites with exsolved nanoparticles are discussed as enhanced electrocatalytic materials.

Nickel Exsolution‐Driven Phase Transformation from an n=2 to an n=1 Ruddlesden‐Popper Manganite for Methane Steam Reforming Reaction in SOFC Conditions

“…Then, under reducing atmosphere and high temperature (driven force), nanosized metallic particles can precipitate from the bulk to the surface. This phenomenon is called in situ growth or exsolution and, as is previously presented, it could be considered as the basis for the design and development of more sophisticated oxide materials with advanced functionality . Even though, such mechanism has been applied mainly for perovskite structural oxides and until now few examples of exsolution in RP compounds have been reported…”

A Reversible Protonic Ceramic Cell with Symmetrically Designed Pr₂NiO_4+δ-Based Electrodes: Fabrication and Electrochemical Features

“…In other words, the total conductivity is determined by oxide phases, since no continuous high conductive metallic framework is formed under such a reduction. Nevertheless, Ni-particles appears during the exsolution procedure (Figure 2c), which is found to be a remarkable factor in electrode processes improvement [31]. According to Figure 2c, a certain part of Pr2O3 is transformed to Otherwise, if Pr(OH)3 was formed during the reduction procedure, the overall weight change should amount to 96.1%.…”

Wrinkled Perovskite La0.9Mn0.6Ni0.4O3−δ Nanofibers as Highly Efficient Electrocatalyst for Rechargeable Li−O2 Batteries

“…Aiming at the key factors, extensive researches have been devoted to developing various active catalysts, including carbon materials, [1][2][3] precious metals or alloys, [4][5][6] transition metal nitrides [7][8][9] and oxides. [10][11][12] As recently reported in the literatures, [13][14][15][16][17] perovskite oxides (ABO 3 ) have become attractive catalysts with prominent advantages of good ORR/OER activity, low cost, high electrochemical stability and relatively high ionic/electronic conductivity, which previously were widely applied in fuel cells. Particularly, the electrocatalytic activity and ionic/electronic transport of perovskites could be improved by remarkable structure design, doping or substituting elements.…”

“…As recently reported in the literatures, perovskite oxides (ABO 3 ) have become attractive catalysts with prominent advantages of good ORR/OER activity, low cost, high electrochemical stability and relatively high ionic/electronic conductivity, which previously were widely applied in fuel cells. Particularly, the electrocatalytic activity and ionic/electronic transport of perovskites could be improved by remarkable structure design, doping or substituting elements.…”