We report here on the high activity and stability of low-content gold–cerium oxide catalysts for the water–gas shift reaction (WGS). These catalysts are reversible in cyclic reduction–oxidation treatment up to 400 8C, are non-pyrophoric, and are thus potential candidates for application to hydrogen generation for fuel cell power production. Low-content (0.2–0.9 at.%) gold–ceria samples were pre...

In this paper we report on the activity of Cuand Ni-containing cerium oxide catalysts for low-temperature water-gas shift (WGS). Bulk catalysts were prepared in nanocrystalline form by the urea co-precipitation–gelation method. Lanthanum dopant (10 at.%) was used as a structural stabilizer of ceria, while the content of Cu or Ni was in the range of 5–15 at.% (2–8 wt.%). At low metal loadings, C...

water alternating gas (wag) technique is used in the petroleum industry to inject carbon dioxide (co2) into underground formations either for sequestration or enhanced oil recovery (eor) processes. co2 injection causes reactions with formation brine or aquifer and produces carbonic acid, the acid dissolves calcite and changes flow behavior significantly. modeling and investigating effects of co...

The high-temperature rate of reaction of the homogeneous, reverse water-gas shift reaction, rWGSR, has been evaluated in quartz reactors with rapid feed pre-heating at low-pressure and high-pressure conditions. The form of the powerlaw rate expression was consistent with the Bradford mechanism. The Arrhenius expressions for the reaction rate constant corresponding to the empty reactor were in v...

The mechanism responsible for the irreversible deactivation of ceria-supported precious metals for the watergas-shift reaction has been investigated through accelerated aging tests. It is shown that deactivation of Pd/ ceria occurs more rapidly at 673 K compared to 523 K when operating with an integral reactor in 25 torr each of CO and H2O. By heating a fresh catalyst in H2, H2O, CO, or CO2, it...

In production of electricity from coal, integrated gasification combined cycle plants typically operate with conventional packed bed reactors for the water-gas shift reaction, and a Selexol process for carbon dioxide removal. Implementation of membrane reactors in place of these two process units provides advantages such as increased carbon monoxide conversion, facilitated CO2 removal/sequestra...

Multiwalled carbon nanotubes (MWCNTs) on a grid supported cobalt nanocatalyst were grown, by exposing it to combustion gases from ethylene/air rich premixed flames. Ten equivalence ratios (φ) were investigated, as follows: 1.37, 1.44, 1.47, 1.50, 1.55, 1.57, 1.62, 1.75, 1.82, and 1.91. MWCNT growth could be observed for the range of equivalence ratios between 1.45 and 1.75, with the best yield ...

CeO2 nanooctahedrons, nanorods, and nanocubes were prepared by the hydrothermal method and were then used as supports of Cu-based catalysts for the water-gas shift (WGS) reaction. The chemical and physical properties of these catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption/desorption, UV-Vis spectroscopy, X-ray photoelectron spectro...

Using operando and transient spectroscopies (IR, Raman, UV-Vis), low-loaded Cu/CeO 2 (111) catalysts were investigated with respect to their redox behavior the importance of adsorbates for reverse water–gas shift (rWGS) reaction.

The gasification of biomass is a promising technique to generate different forms of valuable alternative energy, including direct thermal energy and further conversion of synthesis gas to clean liquid fuels or chemicals via Fischer– Tropsch synthesis (FTS) [1–5]. The ideal H2/CO ratio for FTS is ~2/1 based on the stoichiometry. However, The H2/ CO for the synthesis gas obtained from biomass gas...