Evaluation of nanoparticle zirconia supports in the thermochemical water splitting cycle over iron oxides

Abstract

openAccessArticle: Falsecover date: 2015-12-14pii: S0360-3199(15)30114-2Harvest Date: 2016-01-06 13:08:23issueName:Page Range: 15972-15972href scidir: http://www.sciencedirect.com/science/article/pii/S0360319915301142pubType

Nickel ferrite supported on calcium-stabilized zirconia for solar hydrogen production by two-step thermochemical water splitting

“…Structural characterization of the Ca-doped zirconia sample showed the insertion of Fe ions from the ferrite occupying Zr ion positions in the support lattice (table 2). The presence of these Fe ions into the ZrO2 lattice could be related with the improvement of hydrogen production observed in the Ca-doped zirconia sample because, as indicated in the introduction section, the Fe ions atomically dispersed in the zirconia lattice avoid sintering [34]- [36] and they reduce/react with inert/steam in the reduction/oxidation steps improving the generation of hydrogen respect to unsupported ferrites [16] . The existence of calcium zirconate particles detected by TEM ( Figure 3) and XPS ( Figure S5 and table S4) could also participate in the improvement in stability observed for the F-CSZ sample.…”

A thermochemical study of iron aluminate-based materials: a preferred class for isothermal water splitting

“…28–30 Unlike inert supports ( e.g. , ZrO 2 ) that simply increase diffusion distances as a method to mitigate sintering, 31 the reaction between iron( ii ) oxide (FeO) and alumina (Al 2 O 3 ) to form hercynite 32 helps resist deactivation by increasing the melting point of the iron aluminate material; 29 FeO and FeAl 2 O 4 melt at 1377 °C and 1780 °C, respectively. As a result, samples with higher alumina content exhibit more stable performance at the expense of lowering the proportion of redox-active iron.…”