Matches in SemOpenAlex for { <https://semopenalex.org/work/W2023748128> ?p ?o ?g. }
- W2023748128 endingPage "2804" @default.
- W2023748128 startingPage "2795" @default.
- W2023748128 abstract "It is found that CH4 oxidation over Pt/Al2O3 catalyst at 330–460 °C can stably proceed via two distinctly different regimes at identical feed gas composition: “low activity regime” and “high activity regime”. Switching between the regimes depends on the O2 concentration and the direction of its change. For the reaction mixture with constant methane concentration of 1%, the incremental decrease in O2 concentration from 2.5% (O2/CH4 ∼ 2.5, lean conditions) to ∼1% (O2/CH4 ∼ 1, stoichiometric or rich conditions) results in the catalyst activation and its switching to the high activity regime. The catalyst remains active upon further incremental increase in O2 concentration until reaching O2/CH4 ∼ 2, when switching to low activity regime takes place. Such responses of the catalyst activity to the changes in the feed gas composition result in the appearance of the pronounced concentration hysteresis. The evident correlation between in situ X-ray absorption spectroscopy and catalytic data strongly suggests that the switching of the catalyst between low activity regime and high activity regime, which causes the concentration hysteresis, stems from the change in the electronic state of Pt particles. According to in situ XANES data, the electron density on the Pt particles decreases in the low activity regime, as evidenced by an increased Pt-L3 white line intensity. In contrast, switching the catalyst to high activity regime is accompanied by a decrease in the white line intensity, indicating the electron density increase. In turn, the changes in the Pt electronic state are attributable to changes in the O/Pt surface ratio or formation/decomposition of a two-dimensional layer of surface Pt oxide triggered by variation of oxygen concentration in the reaction mixture. The addition of highly reactive CO or H2 to the reaction mixture shifts the hysteresis loop toward higher oxygen concentration as a result of consuming oxygen in H2 or CO oxidation, which decreases the effective oxygen concentration. In contrast to this, the increase in the methane concentration widens the hysteresis window, presumably because of the different stoichiometry of CH4 oxidation upon catalyst activation (when partial CH4 oxidation prevails) and deactivation (when total oxidation of CH4 predominates)." @default.
- W2023748128 created "2016-06-24" @default.
- W2023748128 creator A5004444741 @default.
- W2023748128 creator A5030867238 @default.
- W2023748128 creator A5055572174 @default.
- W2023748128 creator A5060459445 @default.
- W2023748128 creator A5070318791 @default.
- W2023748128 creator A5070763425 @default.
- W2023748128 creator A5090234523 @default.
- W2023748128 date "2015-03-31" @default.
- W2023748128 modified "2023-10-15" @default.
- W2023748128 title "Concentration Hysteresis in the Oxidation of Methane over Pt/γ-Al<sub>2</sub>O<sub>3</sub>: X-ray Absorption Spectroscopy and Kinetic Study" @default.
- W2023748128 cites W1515698020 @default.
- W2023748128 cites W1817977288 @default.
- W2023748128 cites W1964806650 @default.
- W2023748128 cites W1969883898 @default.
- W2023748128 cites W1977529681 @default.
- W2023748128 cites W1980078076 @default.
- W2023748128 cites W1982263343 @default.
- W2023748128 cites W1982738282 @default.
- W2023748128 cites W1989575187 @default.
- W2023748128 cites W1990891689 @default.
- W2023748128 cites W1991051762 @default.
- W2023748128 cites W1997961465 @default.
- W2023748128 cites W1998831406 @default.
- W2023748128 cites W2008775380 @default.
- W2023748128 cites W2012144862 @default.
- W2023748128 cites W2017930366 @default.
- W2023748128 cites W2023692073 @default.
- W2023748128 cites W2024451528 @default.
- W2023748128 cites W2026125980 @default.
- W2023748128 cites W2026958243 @default.
- W2023748128 cites W2031533535 @default.
- W2023748128 cites W2034330431 @default.
- W2023748128 cites W2038304832 @default.
- W2023748128 cites W2052841701 @default.
- W2023748128 cites W2054495943 @default.
- W2023748128 cites W2056384409 @default.
- W2023748128 cites W2070227796 @default.
- W2023748128 cites W2074093707 @default.
- W2023748128 cites W2075719948 @default.
- W2023748128 cites W2075739530 @default.
- W2023748128 cites W2079587049 @default.
- W2023748128 cites W2080225132 @default.
- W2023748128 cites W2086320284 @default.
- W2023748128 cites W2092523019 @default.
- W2023748128 cites W2111622374 @default.
- W2023748128 cites W2125721491 @default.
- W2023748128 cites W2133308369 @default.
- W2023748128 cites W2169649657 @default.
- W2023748128 cites W2171385314 @default.
- W2023748128 cites W2186490867 @default.
- W2023748128 cites W2317714055 @default.
- W2023748128 cites W2475785589 @default.
- W2023748128 cites W303455123 @default.
- W2023748128 doi "https://doi.org/10.1021/cs501964z" @default.
- W2023748128 hasPublicationYear "2015" @default.
- W2023748128 type Work @default.
- W2023748128 sameAs 2023748128 @default.
- W2023748128 citedByCount "32" @default.
- W2023748128 countsByYear W20237481282015 @default.
- W2023748128 countsByYear W20237481282016 @default.
- W2023748128 countsByYear W20237481282017 @default.
- W2023748128 countsByYear W20237481282018 @default.
- W2023748128 countsByYear W20237481282019 @default.
- W2023748128 countsByYear W20237481282020 @default.
- W2023748128 countsByYear W20237481282021 @default.
- W2023748128 countsByYear W20237481282022 @default.
- W2023748128 countsByYear W20237481282023 @default.
- W2023748128 crossrefType "journal-article" @default.
- W2023748128 hasAuthorship W2023748128A5004444741 @default.
- W2023748128 hasAuthorship W2023748128A5030867238 @default.
- W2023748128 hasAuthorship W2023748128A5055572174 @default.
- W2023748128 hasAuthorship W2023748128A5060459445 @default.
- W2023748128 hasAuthorship W2023748128A5070318791 @default.
- W2023748128 hasAuthorship W2023748128A5070763425 @default.
- W2023748128 hasAuthorship W2023748128A5090234523 @default.
- W2023748128 hasConcept C110715899 @default.
- W2023748128 hasConcept C113196181 @default.
- W2023748128 hasConcept C119824511 @default.
- W2023748128 hasConcept C121332964 @default.
- W2023748128 hasConcept C123299182 @default.
- W2023748128 hasConcept C125287762 @default.
- W2023748128 hasConcept C127413603 @default.
- W2023748128 hasConcept C144082473 @default.
- W2023748128 hasConcept C147789679 @default.
- W2023748128 hasConcept C159985019 @default.
- W2023748128 hasConcept C161790260 @default.
- W2023748128 hasConcept C175708663 @default.
- W2023748128 hasConcept C185592680 @default.
- W2023748128 hasConcept C192562407 @default.
- W2023748128 hasConcept C2778591166 @default.
- W2023748128 hasConcept C32891209 @default.
- W2023748128 hasConcept C42360764 @default.
- W2023748128 hasConcept C43617362 @default.
- W2023748128 hasConcept C55493867 @default.
- W2023748128 hasConcept C62284982 @default.
- W2023748128 hasConcept C62520636 @default.