LSCM perovskites

A-site cations, could affect the electrical conductivity through changes in charge carrier mobility. The electrical conductivity was shown to change when substituting La with Mg and Ba, but this was mostly due to the formation of secraidary phases [72]. Apart from Sr, only substitution with Ca resulted in a phase-pure perovskite, but without an increase in conductivity compared to LSCM [72], Furthermore, the introduction of Ca is expected to result in the instability of LSCM under reducing conditions [73]. 

Although the exact reaction mechanism is unclear, general concepts regarding the fuel oxidatiOTi reaction on LSCM have been described in the literature. Yamazoe and Teraoka pointed out that high-temperature oxidation reactions on perovskites typically occur through a reduction-oxidation cycle of the catalysts, otherwise known as a Mars-van Krevelen-type (MvK) mechanism [75], with the B-site elements serving as the redox centers. Studies suggest that this is the case for LSCM. 

For perovskite-based fuel electrodes, Mn-doped lanthanum strontium chromite (Lao.75Sro25Mno.5Cro.5O3, LSCM), developed by Tao and Irvine, has been infiltrated with ceria-based materials by other research groups, who reported that an improved electrocata-lytic activity was achieved when tested with various fuels. " Without infiltration of a ceria phase into LSCM-YSZ anodes, the oxidation of methane was considered to be limited by insufficient oxygen ion conductivity in the lanthanum chromite-based materials. Gd-doped ceria has higher oxide ion conductivity than LSCM, which is also illustrated by an improved performance of these infiltrated electrodes. The mechanism of methane oxidation in Gd-doped ceria-infiltrated LSCM anodes in wet CH4 was considered to involve the partial oxidation of methane by a gas/solid reaction between ceria and methane-generating CO and H2, followed by electrochemical oxidation of the products. The added ceria also suppressed coke formation in these anodes. ... 

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