ChemInform Abstract: Perovskites and Their Nanocomposites with Fluorite‐Like Oxides as Materials for Solid Oxide Fuel Cells Cathodes and Oxygen‐Conducting Membranes: Mobility and Reactivity of the Surface/Bulk Oxygen as a Key Factor of Their Performance

Modern Trends in Design of Catalysts for Transformation of Biofuels into Syngas and Hydrogen: From Fundamental Bases to Performance in Real Feeds

“…Ester polymeric precursors (Pechini) method [88] is based upon using citric acid and ethylene diamine as chelating agents. With ethylene glycol solution single-phase nanocrystalline doped cerium-zirconium oxides [13,18,89], perovskites [31,32,34,35] and spinel oxides [69] were obtained possessing a high spatial uniformity of cations distribution. In the case of aqueous solutions such spatial uniformity was not obtained [62][63][64][65].…”

“…The method of synthesis should provide a high dispersion of complex oxides along with spatial uniformity of elements distribution in their particles. A lot of methods including co-precipitation, solvothermal method, sol-gel method, Pechini polymeric precursor method, microemulsions, sonochemical method, microwave-assisted self-combustion and ultrasonic spray pyrolysis were used for synthesis of oxides [30,33,35,36,87]. Among advanced methods, synthesis in flow regimes (including that in supercritical conditions) characterized by continuous generation of nanoparticles appears to be very promising [20][21][22][23][24][25][26]87].…”

“…use mixed oxides of rare earth and transition metals with variable oxidation states of cations/oxygen stoichiometry. As the result, such oxides with fluorite [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], perovskite and spinel [68][69][70][71][72][73][74][75][76] structures as well as their nanocomposites [35,72,73] have sufficient amount of reactive surface/bulk oxygen species characterized also by a high mobility providing their fast migration to metal particles, where they react with activated fuel molecules, thus preventing coking [71][72][73]. These oxides are the most promising supports for catalysts of hydrocarbons or oxygenates reforming to syngas without coking .…”

“…These oxides are the most promising supports for catalysts of hydrocarbons or oxygenates reforming to syngas without coking . Their oxygen mobility can be tuned by changing their composition as well as synthesis procedures [13,32,35]. 2.…”

“…The most important new aspect of this review is detailed description of oxygen mobility in catalysts of fuels transformation into syngas comprised of mixed oxides with fluorite, perovskite and spinel structures promoted with Ni and Pt-group metals. It is based on application of unique techniques of oxygen isotope heteroexchange of these catalysts with 18 O2 or C 18 O2 in the gas phase in flow installations including experiments in the temperature-programmed mode as well as in the steady-state of catalytic reactions (Steady-State Isotope Transients Kinetic Analysis, SSITKA) [18,35,68,69,71,72,87]. Even though it is well known that a high oxygen mobility and reactivity in these catalysts allows to prevent coking in the reactions of biofuels transformation into syngas by a fast transfer of oxygen species to the metal-support interface, where they interact with activated fuels fragments transforming them into syngas, only in our works such strict characteristics of oxygen mobility as oxygen self-diffusion coefficients were systematically estimated using sophisticated software for isotope exchange kinetics data analysis.…”