The role of chromium in iron-based high-temperature water-gas shift catalysts under industrial conditions

Kód výsledku v IS VaVaI

RIV/00216208:11320/21:10439410 - isvavai.cz

Výsledek na webu

https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=XhQ1~gmcCO

DOI - Digital Object Identifier

10.1016/j.apcatb.2021.120465

Jazyk výsledku

angličtina

Název v původním jazyce

The role of chromium in iron-based high-temperature water-gas shift catalysts under industrial conditions

Popis výsledku v původním jazyce

Chromium promotion of iron oxide based water-gas shift (WGS) catalysts prepared via co-precipitation/calcination was investigated. Mossbauer spectroscopy and XRD evidence that chromium is incorporated in the calcined hematite (alpha-Fe2O3) precursor irrespective of the doping level (0-12 wt.%). CO-TPR shows chromium delays the reduction of hematite and the active magnetite (Fe3O4) phase. WGS activity was evaluated under realistic conditions for 4 days. Enhanced CO conversion was observed with increased chromium doping. Mossbauer spectra indicate that chromium incorporates into octahedral sites of magnetite and prevents reduction of Fe3+ to Fe2+ during formation of the active phase, leading to an increased Fe3+/Fe2+ ratio in octahedral sites. The higher Fe3+/Fe2+ ratio did not affect the high CO conversion associated with the structural stabilization mechanism of Cr-doping. Interpretation of the Mossbauer spectra was supported by computational modelling of various chromium and vacancy-doped magnetite structures. The bulk structure of an in situ prepared chromium-doped high-temperature WGS catalyst is best described as a partially oxidized chromium-doped magnetite phase. No surface effects of Cr-doping were found.

Název v anglickém jazyce

The role of chromium in iron-based high-temperature water-gas shift catalysts under industrial conditions

Popis výsledku anglicky

Chromium promotion of iron oxide based water-gas shift (WGS) catalysts prepared via co-precipitation/calcination was investigated. Mossbauer spectroscopy and XRD evidence that chromium is incorporated in the calcined hematite (alpha-Fe2O3) precursor irrespective of the doping level (0-12 wt.%). CO-TPR shows chromium delays the reduction of hematite and the active magnetite (Fe3O4) phase. WGS activity was evaluated under realistic conditions for 4 days. Enhanced CO conversion was observed with increased chromium doping. Mossbauer spectra indicate that chromium incorporates into octahedral sites of magnetite and prevents reduction of Fe3+ to Fe2+ during formation of the active phase, leading to an increased Fe3+/Fe2+ ratio in octahedral sites. The higher Fe3+/Fe2+ ratio did not affect the high CO conversion associated with the structural stabilization mechanism of Cr-doping. Interpretation of the Mossbauer spectra was supported by computational modelling of various chromium and vacancy-doped magnetite structures. The bulk structure of an in situ prepared chromium-doped high-temperature WGS catalyst is best described as a partially oxidized chromium-doped magnetite phase. No surface effects of Cr-doping were found.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Applied Catalysis B: Environmental

ISSN

0926-3373

e-ISSN

—

Svazek periodika

297

Číslo periodika v rámci svazku

25 June 2021

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

14

Strana od-do

120465

Kód UT WoS článku

000696992600002

EID výsledku v databázi Scopus

2-s2.0-85109081027