Partial oxidation of methane on Pt-supported lanthanide doped ceria–zirconia oxides: Effect of the surface/lattice oxygen mobility on catalytic performance

Syngas Generation from Methane Using a Chemical‐Looping Concept: A Review of Oxygen Carriers

“…Kang and Eyring [17,18] investigated the activity of the Ce-Zr-Tb-O system for methane oxidation and found that the oxygen transfer capacity and the oxygen storage capacity are equally important for syngas generation. The reactivity of ceria-zirconia oxides doped by Pr, Gd, or La for methane conversion was also investigated by CH 4 -TPR technology and pulse reduction experiments, and it is proved that Pr-doped sample showed good activity for syngas generation [19]. The reaction between methane and Ce-Zr-Pr-O oxygen carrier with Pt as catalyst at high temperatures is controlled by the lattice oxygen diffusion, while the reactivity of weak bound surface oxygen determine the activity of the mixed oxides at the lowest temperature (∼550 ∘ C).…”

Methods of isotopic relaxations for estimation of oxygen diffusion coefficients in solid electrolytes and materials with mixed ionic-electronic conductivity

“…Mobility of lattice oxygen is an important factor deter mining high performance and stable operation of such systems. Introduction of rare-earth metal cations into cerium-zirconium mixed oxides stabilizes their struc ture and allows regulating oxygen mobility [10,11].…”

Modeling of transient studies on the reaction kinetics over catalysts with lattice oxygen mobility: Dry reforming of CH4 over a Pt/PrCeZrO catalyst

“…These processes have different time scales, and their impact on transient behavior of the system can be rather complex. A number of studies have revealed that for the oxide catalysts the bulk oxygen mobility can play an important role in the system dynamics [4,[10][11][12][13][14][15][16]. Near-surface oxygen mobility of solid catalysts strongly affects not only the character of transient regimes, but activity, selectivity, and stability of the catalysts performance because the surface state and, respectively, the reaction rates are determined both by transformations of the reactive surface species and the oxygen transport to the surface from the bulk layers of catalyst particle.…”

“…For example, the impact of oxygen mobility on the catalyst properties was studied for nanocrystalline Pt/LnCeZrO catalysts doped with rare-earth elements (Ln = Gd, Pr, La) in partial oxidation of methane, methane steam/dry reforming, and autothermal reforming of acetone into syngas [14][15][16][17][18][19][20][21][22][23][24]. Due to strong interaction of supported Pt with doped ceria-zirconia oxides, after pretreatment of catalysts in O 2 it is mainly present as Pt 2+ and Pt 4+ cations (XPS data [18]) possessing a high ability to activate CH 4 as revealed by TAP (Temporal Analysis of Products) [20] and transient [14,16,19,20] studies.…”

“…The rates of near-surface (as well as along domain boundaries) or bulk oxygen diffusion estimated for doped ceria-zirconia oxides with supported Pt by analysis of the oxygen isotope exchange data/chemical transients are high enough (oxygen diffusion coefficients D V in the range of 10 -12 10 -14 cm 2 /s at 600-700 o C [14][15][16][24][25][26][27]) to provide the required rates of oxygen transfer to the metal-support interface.…”