CO2 dry reforming of CH4 with Sr and Ni co-doped LaCrO3 perovskite catalysts

Investigation of hetero-phases grown via in-situ exsolution on a Ni-doped (La,Sr)FeO3 cathode and the resultant activity enhancement in CO2 reduction

“…As the temperature rises, diffusion of the B-site ions to the surface, and their reduction takes place, as already discussed with ETEM results. The first set of peaks with maxima at 457 °C, 520 °C and 536 °C can, therefore, be assigned [48] to the partial reduction of Fe 3+ and Ni 3+ ions to lower valent cations [30,48,49]. Some of these lower valent cations can be metallic as seen from ETEM results.…”

“…While Barnet's group was one of the first to use this concept for solid oxide fuel cell electrodes [26], Irvine and his co-workers performed extensive investigations into the exsolution process and showed the formation of various transition metal nanoparticles from nonstoichiometric perovskites under a reducing environment and also under applied potential in a solid oxide electrolyte cell [5,19,22,23]. While a major portion of the studies were done on the exsolution of Ni/Fe/Co nanoparticles on doped strontium titanate perovskites [4,5,11,16,18,19,[27][28][29], there have been a few investigations into other perovskite systems such as Ni-doped (La,Sr) 1-x CrO 3 [6,30], La 0.3 Sr 0.7 Cr 0.3 Fe 0.6 Co 0.1 O 3−δ [31], (La 0.75 Sr 0.25 )(Cr 0.5 Fe 0.35 Ni 0.15 )O 3 [22], La 0.9 Mn 0.8 Ni 0.2 O 3 [32], as well as double perovskite materials such as Co-doped Pr 0.5 Ba 0.5 MnO x [17] and Ni-doped Sr 2 Fe 1.5 Mo 0.5 O 6 [33,34].…”

Progress and Opportunities for Exsolution in Electrochemistry

“…Under conditions where carbonaceous feeds are used, carbon accumulation (coking) can impede the longevity of the device, making it industrially irrelevant. Exsolution catalysts have been thoroughly studied under a variety of methane oxidation conditions which are susceptible to coking [37,[41][42][43][44][45]. It was found that the strong MSI imbued by the socketed configuration between the metal and the support was able to mechanically block the tip-growth mechanism by which multi-walled carbon nanotubes (MWCNTs) grow.…”

Exsolution of nanoparticles on A-site-deficient lanthanum ferrite perovskites: its effect on co-electrolysis of CO2 and H2O

“…In situ studies using an environmental transmission electron microscopy (ETEM) and density functional theory (DFT) revealed the growth and kinetics of Ni and Co nanoparticles. [31][32][33][34][35][36] Research on exsolution from perovskites has been focused mainly on metal nanoparticles and strontium titanate with its simple cubic structure. On the other hand, strontium-doped lanthanum ferrite (LSF) perovskites are characterized by a wide range of crystal structures (orthorhombic, rhombohedral, tetragonal, or cubic) dependent on the preparation method, the dopants used, and the temperatures.…”