Matches in SemOpenAlex for { <https://semopenalex.org/work/W2582071875> ?p ?o ?g. }
- W2582071875 endingPage "214" @default.
- W2582071875 startingPage "203" @default.
- W2582071875 abstract "In situ diffuse reflectance mode (DRIFTS) measurements for adsorption of CO and under the water-gas shift (WGS) reaction revealed that formates emerge on the surface of reduced ceria after the reaction of CO with geminal OH groups. These groups are formed after reduction of the ceria surface shell. X-ray absorption near edge spectroscopy (XANES) results demonstrated that the process of surface shell reduction was strongly catalyzed by the presence of metal, while changing very little, if at all, the catalysis of bulk ceria reduction. For 1% Pt/ceria, under steady state WGS at a high H2O/CO ratio, surface formate concentrations were strongly limited at high CO conversions, while Pt-CO was affected only slightly. Under high H2O/CO ratios, CO exhibits a first order rate dependency, and therefore, the active site is expected to move to sparser coverages of CO, which suggested that the WGS mechanism likely proceeded via formates. Later, XANES work gave no evidence for the reoxidation of ceria surface by water under a hydrogen environment, which would be necessary to substantiate an alternate mechanism, referred to as the ceria-mediated redox process. Later, isotope switching from H2O to D2O was carried out to validate the possibility that decomposition of surface formates could be the rate limiting step for the mechanism, as was proposed and demonstrated earlier by Shido and Iwasawa. In agreement with their findings, we also observed a normal isotope effect, consistent with a link between the activation energy barrier of the rate limiting step to the breaking of the CH bond of the formate. In this study, a variety of metals were screened to try to gain further insight into the role played by the metal in the catalysis of metal/ceria systems for WGS. One group of metals was selected on the basis of reduction temperature, since spillover from reduced metal likely catalyzes the reduction of ceria surface. Therefore, we tested the following metals, moving from lowest to highest reduction temperature: Pt<Ni<Co=Fe. These were found to catalyze reduction of ceria surface by the same trend, as well as the WGS rate. In each case, DRIFTS showed that as reduction of ceria surface occurred, marked increases in geminal OH intensities occurred, which yielded formates upon adsorption of CO. The second group of metals was a comparative study between Pt and Group 11 metals that have been purported to catalyze surface reduction at the same or even lower temperatures than Pt. Indeed, the surface reduction occurred at a lower temperature than for Pt with Au and at a similar temperature with Cu. However, on an equivalent atomic basis, the depth of reduction of ceria was found to be higher when Pt was used over Au, and the WGS rate was about 20 times higher with Pt than by Group 11 metal promotion at 250 °C and higher. WGS feed conditions were carefully chosen to mimic conditions found in a fuel cell reformer." @default.
- W2582071875 created "2017-02-03" @default.
- W2582071875 creator A5019529061 @default.
- W2582071875 creator A5021784872 @default.
- W2582071875 creator A5047458262 @default.
- W2582071875 creator A5055565392 @default.
- W2582071875 creator A5057937054 @default.
- W2582071875 creator A5077983914 @default.
- W2582071875 creator A5083054138 @default.
- W2582071875 date "2004-02-20" @default.
- W2582071875 modified "2023-10-03" @default.
- W2582071875 title "Water-gas shift: comparative screening of metal promoters for metal/ceria systems and role of the metal" @default.
- W2582071875 cites W1992638677 @default.
- W2582071875 cites W1993417369 @default.
- W2582071875 cites W2019616910 @default.
- W2582071875 cites W2019654293 @default.
- W2582071875 cites W2020682670 @default.
- W2582071875 cites W2033955352 @default.
- W2582071875 cites W2040298173 @default.
- W2582071875 cites W2083886909 @default.
- W2582071875 cites W2090847735 @default.
- W2582071875 cites W2125190194 @default.
- W2582071875 cites W2380548727 @default.
- W2582071875 cites W2517647103 @default.
- W2582071875 doi "https://doi.org/10.1016/j.apcata.2003.09.007" @default.
- W2582071875 hasPublicationYear "2004" @default.
- W2582071875 type Work @default.
- W2582071875 sameAs 2582071875 @default.
- W2582071875 citedByCount "215" @default.
- W2582071875 countsByYear W25820718752012 @default.
- W2582071875 countsByYear W25820718752013 @default.
- W2582071875 countsByYear W25820718752014 @default.
- W2582071875 countsByYear W25820718752015 @default.
- W2582071875 countsByYear W25820718752016 @default.
- W2582071875 countsByYear W25820718752017 @default.
- W2582071875 countsByYear W25820718752018 @default.
- W2582071875 countsByYear W25820718752019 @default.
- W2582071875 countsByYear W25820718752020 @default.
- W2582071875 countsByYear W25820718752021 @default.
- W2582071875 countsByYear W25820718752022 @default.
- W2582071875 countsByYear W25820718752023 @default.
- W2582071875 crossrefType "journal-article" @default.
- W2582071875 hasAuthorship W2582071875A5019529061 @default.
- W2582071875 hasAuthorship W2582071875A5021784872 @default.
- W2582071875 hasAuthorship W2582071875A5047458262 @default.
- W2582071875 hasAuthorship W2582071875A5055565392 @default.
- W2582071875 hasAuthorship W2582071875A5057937054 @default.
- W2582071875 hasAuthorship W2582071875A5077983914 @default.
- W2582071875 hasAuthorship W2582071875A5083054138 @default.
- W2582071875 hasConcept C110715899 @default.
- W2582071875 hasConcept C121332964 @default.
- W2582071875 hasConcept C147789679 @default.
- W2582071875 hasConcept C150394285 @default.
- W2582071875 hasConcept C161790260 @default.
- W2582071875 hasConcept C178790620 @default.
- W2582071875 hasConcept C179104552 @default.
- W2582071875 hasConcept C185592680 @default.
- W2582071875 hasConcept C190463131 @default.
- W2582071875 hasConcept C194439259 @default.
- W2582071875 hasConcept C204242273 @default.
- W2582071875 hasConcept C2780178953 @default.
- W2582071875 hasConcept C32891209 @default.
- W2582071875 hasConcept C512968161 @default.
- W2582071875 hasConcept C544153396 @default.
- W2582071875 hasConcept C55493867 @default.
- W2582071875 hasConcept C62520636 @default.
- W2582071875 hasConcept C66114498 @default.
- W2582071875 hasConceptScore W2582071875C110715899 @default.
- W2582071875 hasConceptScore W2582071875C121332964 @default.
- W2582071875 hasConceptScore W2582071875C147789679 @default.
- W2582071875 hasConceptScore W2582071875C150394285 @default.
- W2582071875 hasConceptScore W2582071875C161790260 @default.
- W2582071875 hasConceptScore W2582071875C178790620 @default.
- W2582071875 hasConceptScore W2582071875C179104552 @default.
- W2582071875 hasConceptScore W2582071875C185592680 @default.
- W2582071875 hasConceptScore W2582071875C190463131 @default.
- W2582071875 hasConceptScore W2582071875C194439259 @default.
- W2582071875 hasConceptScore W2582071875C204242273 @default.
- W2582071875 hasConceptScore W2582071875C2780178953 @default.
- W2582071875 hasConceptScore W2582071875C32891209 @default.
- W2582071875 hasConceptScore W2582071875C512968161 @default.
- W2582071875 hasConceptScore W2582071875C544153396 @default.
- W2582071875 hasConceptScore W2582071875C55493867 @default.
- W2582071875 hasConceptScore W2582071875C62520636 @default.
- W2582071875 hasConceptScore W2582071875C66114498 @default.
- W2582071875 hasIssue "2" @default.
- W2582071875 hasLocation W25820718751 @default.
- W2582071875 hasOpenAccess W2582071875 @default.
- W2582071875 hasPrimaryLocation W25820718751 @default.
- W2582071875 hasRelatedWork W1974380584 @default.
- W2582071875 hasRelatedWork W1983480124 @default.
- W2582071875 hasRelatedWork W2022190308 @default.
- W2582071875 hasRelatedWork W2052230187 @default.
- W2582071875 hasRelatedWork W2072122623 @default.
- W2582071875 hasRelatedWork W2086393434 @default.
- W2582071875 hasRelatedWork W2094565162 @default.
- W2582071875 hasRelatedWork W2125159628 @default.
- W2582071875 hasRelatedWork W350624296 @default.