Cerium ion redox system in CeO2–xFe2O3 solid solution at high temperatures (1,273–1,673 K) in the two-step water-splitting reaction for solar H2 generation

High-temperature isothermal chemical cycling for solar-driven fuel production

“…To this 125 ml of NH 4 OH was added to achieve pH = 10. The solution was then heated to and maintained at 80 1C on a hot plate and stirred at 400 rpm until gelation.…”

“…[1][2][3][4][5][6][7] The reaction scheme, as written out explicitly for the case of H 2 production from H 2 …”

A thermochemical study of ceria: exploiting an old material for new modes of energy conversion and CO 2 mitigation

“…In totality, these considerations suggest that ceria, which undergoes substantial oxygen stoichiometry changes without a change in crystal structure, has an extremely high melting temperature of approximately 2800 K, and displays high catalytic activity towards carbon-containing gases (Jin et al 1987;Trovarelli 1996;Murray et al 1999;Park et al 2000;Sharma et al 2000;Demoulin et al 2007), is an attractive material for thermochemical fuel production. Indeed, preliminary reports of the suitability of ceria for this technology have appeared in the recent literature (Abanades & Flamant 2006;Kaneko et al 2007Kaneko et al , 2008Kang et al 2007;Miller et al 2008;Kaneko & Tamaura 2009). Here, the reaction scheme (figure 1) involves a partial reduction at high temperature rather than a stoichiometric phase change.…”

Ceria as a Thermochemical Reaction Medium for Selectively Generating Syngas or Methane from H2O and CO2

“…Furthermore, ceria-based oxides are known as active catalyst supports and oxygen storage materials with high resistance to carbon deposition. [7][8][9] These observations, as well as recent demonstrations of H 2 production from CeO 2 , [10][11][12][13][14][15] led us to consider the possibility of using ceria-based oxides for simultaneous thermochemical reduction of H 2 O and CO 2 to produce carbon-containing fuels.We selected 15 % samarium-doped ceria (SDC) to serve as a test-bed for ceria-based fuel production, because the thermodynamics of reduction are well-characterized.[16] Hence, the value of oxygen nonstoichiometry, d, in the chemical formula Sm 0.15 Ce 0.85 O 1.925Àd is known for a given temperature and oxygen partial pressure. We examined the fuel production halfcycle using porous SDC, pretreated at 1500 8C for 24 h, to simulate possible deactivation resulting from sintering and then lightly reduced the material to a specified d value (typically 0.05 for experimental convenience).…”