Isovalent and aliovalent substitution effects on redox chemistry of Sr2MgMoO6−δ SOFC-anode material

Role of SrMoO4 in Sr2MgMoO6 synthesis

“…Fig. 6 shows, as an example, the XRD patterns for the Sr 2 MgMoO 6 -SrMoO 4 system with 20 wt% of SrMoO 4 after synthesis in air and for the same sample after reduction in 5% H 2 /Ar at 850 1C for 12 h. It can be seen that SrMoO 4 in the as-synthesized sample has been completely Pure Sr 2 MgMoO 6 shows a linear behavior in the Arrhenius-plot, as has been found in our previous study [12], with electrical conductivity of ca. 2 S/cm at 800 1C.…”

“…Second, we consider some issues related to SrMoO 4 that is a common impurity in Sr 2 MgMoO 6 samples [10][11][12] and in related Sr-Mo-O samples [13]. The SrMoO 4 compound with a scheelite structure and Mo at the oxidation state þVI is a white and insulating material [14].…”

Solid Oxide Fuel Cell Anode Materials for Direct Hydrocarbon Utilization

“…[ 382 ] Ca 2 FeMoO 6 , Sr 2 FeMoO 6 , and Ba 2 FeMoO 6 crystallized in monoclinic, tetragonal, and cubic structures, respectively, of which Sr 2 FeMoO 6 showed the best fuel cell performance with P max of 0.83 and 0.74 W cm − 2 in dry H 2 and commercial city gas at 850 ° C, respectively. [ 385 ] The aliovalent substitution of B and B´ sites of SMMO (Al, [ 387 ] Co, [ 386 , 388 , 389 ] Ni, [ 386 , 389 , 390 ] Fe, [ 386 , 389 , 391 , 392 ] Mn, [ 386 , 389 ] and Zn [ 389 ] substituting Mg; W and Nb [ 393 ] substituting Mo [ 393 ] ) lowers the degree of cation ordering as well as creates oxygen vacancies in the lattice, both of which seem benefi cial to SOFC anode materials. 5% substitution of Mg by Al, i.e.…”

Optimization of proton conductors for application in solid oxide fuel cell technology

“…Ba2-xSrxM2-xMoxO6-δ and Ba2-xSrxM2-xWxO6-δ, M: Mg, Fe, Co, Ni, etc.) are more tolerant to carbon deposition than Ni-based cermets [41,42]. Interestingly, these compounds are also tolerant to a changing oxygen partial pressure, which allows for example to flush the anode with air, in order to remove any sulfur or carbon species adsorbed on the electrode, and thereby to regenerate the electrode after sulfur or coke deactivation.…”