Enhanced Chemical looping oxidative coupling of methane by Na-doped LaMnO3 redox catalysts

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

“…On a 018Na-LaMnO 3 sample, a C 2 yield of 20% can be obtained at 825 °C. 28 More recently, our research has revealed that the surface-modification of BaSnO 3 with BaBr 2 can significantly improve the amount of surface oxygen vacancies, thus, promoting the generation of active O 2 2− and O 2− species. 29 The O 2 2− peroxide species can directly convert methane to ethylene through a carbene intermediate, which enhances the ethylene selectivity remarkably.…”

“…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. ,− Ding et al found that the surface enrichment by A-site elements on the ABO 3 compounds can improve the OCM performance, but the enrichment of the B-site elements leads to the complete oxidation of methane . Wu et al adjusted the surface chemical compositions of SrTiO 3 and found that the surface enrichment of Sr increased the methane conversion and C 2 product selectivity.…”

“…This oxygen species is beneficial to C 2 hydrocarbon formation. On a 018Na-LaMnO 3 sample, a C 2 yield of 20% can be obtained at 825 °C . More recently, our research has revealed that the surface-modification of BaSnO 3 with BaBr 2 can significantly improve the amount of surface oxygen vacancies, thus, promoting the generation of active O 2 2– and O 2– species .…”

Enhanced C2+selectivity in plasma-assisted chemical looping oxidative coupling of methane using (Na, Li, and K) doped LaMnO3

“…In this work, we report on alkali metal doped x-LaMnO 3 (x = Li, K, and Na) oxygen carriers for plasma-assisted CLOCM. 40 The result manifested the improved CH 4 conversion (9.85%) and C 2+ selectivity (88.71%) by the K dopant. To illustrate the driving force behind the improved performance, a combination of characterization tests and theoretical calculations were carried out to uncover the underlying mechanism.…”

Mixed oxides as multi-functional reaction media for chemical looping catalysis

“…52–94 Furthermore, marrying the chemical looping strategy with oxidative catalysis offers a unique opportunity to intensify the production of a few important commodity chemicals with substantially decreased energy consumption and CO 2 emissions. 95–136 Given that separation processes consume ∼60% of the total energy usage in chemical and petroleum industries and heterogeneous catalysts are responsible for >80% of all chemical products worldwide, chemical looping catalysis (CLCa) in this article, has the potential to facilitate process intensification throughout the chemical manufacturing sector by combining catalytic reactions with separations. 120,137–142 The abovementioned chemical looping process types are summarized in Table 1.…”