Studies of CaTio3 based catalysts for the oxidative coupling of methane

Replacement of Ca by Ni in a Perovskite Titanate to Yield a Novel Perovskite Exsolution Architecture for Oxygen‐Evolution Reactions

“…Comparing the physical characteristics of the two samples, one can observe a large variation in specific surface area (SSA) (Figure c; Figure S6, Supporting Information). The SSA of the Ni‐exsolved CaTiO 3 spheres was greatly increased to 17.310 m 2 g −1 compared with 1.191 m 2 g −1 of the micrometer scaled prepared by solid‐state reactions and 2.981 m 2 g −1 of the mixtures: wet‐chemical (>10 m 2 g −1 ), mechanochemical (<6 m 2 g −1 ) . The higher SSA value results from the sub‐micrometer perovskite scaffold with nanoporous structures and spherical morphology.…”

A+1Nb5+O3 (A = Li, Na, K) Perovskites with Different Fine Structures for Oxidative Coupling of Methane: Tracing the Crystalline Phase Effect on the Surface Active Sites

“…19,20 Through partially replacing the A-and Bsites with heterovalent cations of an ABO 3 perovskite, the surface basicity and O 2− vacancy concentration can be further tailored, which can extend to the surface and facilitate the generation of those active sites needed by the OCM reaction. 21,22 As previously reported, the OCM reaction performance on perovskites is influenced by surface A/B-site molar ratios, preparation methods, heterovalent cation doping, and modification with metal oxides and halides. 16,23−29 Ding et al…”

“…21 It was proved previously that the p-type feature is favorable for OCM reaction. 21 The oxygen ion conductivity of the A +1 Nb 5+ O 3 compounds follows the sequence of NaNbO 3 > KNbO 3 > LiNbO 3 , which are in good agreement to the tolerance factor and unit cell free volume results.…”

“…Over the past decades, quite a lot of catalysts have been studied, particularly including Mn/Na 2 WO 4 /SiO 2 , − Li/MgO, − rare earth oxides, − and perovskites. − Studies have substantiated that ABO 3 perovskites with an alkaline earth or rare earth metal A-site can often stand high temperatures and have potential applications for OCM. , Furthermore, the presence of A-site alkaline earth or rare earth metals can also provide surface basicity for ABO 3 compounds to stabilize the surface active oxygen anions such as O 2 – , O 2 2– , and O – , − which are important for an efficient OCM catalyst. On the other hand, by combining with different B-sites, the B–O bond strength could be tuned, which can influence the reducibility of the lattice O 2– and its surface vacancy concentration. , Through partially replacing the A- and B-sites with heterovalent cations of an ABO 3 perovskite, the surface basicity and O 2– vacancy concentration can be further tailored, which can extend to the surface and facilitate the generation of those active sites needed by the OCM reaction. , …”

Reactivity of Au/La1-xSrxCr1-yNiyO3-δ toward Oxidative Coupling of Methane for C2 and C3 Hydrocarbons Production

“…It is well established that the use of suitable catalyst at the electrode of SOFC is the key issue for achieving the good SOFC cogeneration performance. Recently, several types of catalyst for OCM reaction have been studied and reported, from which the suitable catalysts for this reaction include SrF2/Nd2O3, Mn/Na2WO4/SiO2, La2O3, LaAlO3, LaCoO3,LaCrO3, BaxSr1-xTiO3, SrTi1-xLixO3 and Au/LSM [8][9][10][11][12][13][14][15][16][17]. Among these catalysts, the use of perovskite material (ABO3) as the catalyst as well as the support for the OCM reaction has been widely reported to enhance the good activity in term of product yield and product selectivity [18][19][20][21][22][23][24][25][26][27].…”