The Effect of SnO2Addition to Li/MgO Catalysts for the Oxidative Coupling of Methane

SnO2Based Catalysts with Low‐Temperature Performance for Oxidative Coupling of Methane: Insight into the Promotional Effects of Alkali‐Metal Oxides

“…Tin dioxide has been reported previously to be a very good oxidation catalyst, especially after its lattice matrix is doped with secondary metal cations to form solid solution structures, as found by this group , . Nevertheless, SnO 2 related catalysts have been rarely used for the oxidative coupling of methane, and SnO 2 is mainly adopted as a catalyst additive , . Based on the abovementioned former studies, it is postulated that by using alkali‐metal oxides to tune the surface of SnO 2 , catalytic materials with both abundant alkaline sites and redox sites might be achieved, which could match well the active site requirements for effective OCM catalysts.…”

“…The investigated catalysts can be divided roughly into two groups, the nonredox and the redox types. As a typical example, for the nonredox type catalysts, Li/MgO catalysts have been reported to be effective for reactions in which the surface alkaline sites and oxygen species are regarded as the active sites , . However, Li/MgO catalysts still suffer from deactivation, due to the vaporization of Li + cations .…”

Studies on the behavior of mixed-metal oxides: Adsorption of CO and NO on MgO(100), NixMg1−xO(100), and CrxMg1−xO(100)

“…And third, these are the typical concentrations used in metal-doped MgO catalysts. 3,12,13,[15][16][17][18][19] The core-level XPS spectra of the mixed-metal-oxide films displayed peak positions characteristic of Mg 2ϩ , Ni 2ϩ , and Cr 2ϩ ions. [23][24][25] Experiments of ISS revealed that the surfaces of the oxide films had a composition somewhat different from the ''bulk'' composition determined from XPS.…”

“…[12][13][14][15] In these solid solutions, the second metal ͑or dopant agent͒ is occupying magnesium sites within the typical rocksalt structure of MgO. Metal-doped MgO is active as a catalyst for the oxidative coupling of methane to produce C 2 hydrocarbons, [16][17][18] the reforming of CH 4 with CO 2 or H 2 O, 12,13 DeNOx, 3,15 and DeSOx processes. 19 Thus, in general terms, it is important to know that determines the chemical reactivity of metal-doped MgO.…”

“…Big variations in catalytic activity have been observed when changing the second metal or dopant agent. 12,13,15,16,19 The causes for this phenomenon are not well understood and more basic knowledge is necessary for improving the performance of metal-doped MgO catalysts. The modern techniques of surface science are ideal for addressing this issue.…”