The kinetics of the CO2/H2 reaction over ZnAl2O4 and Cu–ZnAl2O4 catalysts at 250°C up to 0.3 MPa have been followed by in situ FT-IR spectroscopy. Both methanol and carbon monoxide formation were enhanced in presence of copper. They were also produced by independent routes through different adsorbed species. Formate (type I, I′ and II), methoxy and carbonate species were identified on the support and, in addition, copper formate and copper carbonyl species when copper was present. The hydrogenation of carbonate species to copper formate species was found rate determining in methanol synthesis over the Cu–ZnAl2O4 catalyst whereas type I formate species were shown to be the active intermediate for this reaction over the ZnAl2O4 support. Carbon monoxide resulted from the water gas shift reaction probably through the same species as methanol formed over the Cu–ZnAl2O4 catalyst whereas it seemed to stem from formate species of type II in the case of the ZnAl2O4 support. Type II formate species were shown inactive in presence of copper whereas the methoxy species adsorbed on the support were found inactive in presence and in absence of copper. The comparison of these results with those previously obtained with the CO/H2 mixture showed that the nature and the role of the detected species strongly depended on the reactive atmosphere and on the presence or not of copper in the catalyst composition.

EXPLOR_STEP=$WICRI_ROOT/Wicri/Musique/explor/MonteverdiV1/Data/France/Analysis

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{{Explor lien
   |wiki=    Wicri/Musique
   |area=    MonteverdiV1
   |flux=    France
   |étape=   Analysis
   |type=    RBID
   |clé=     ISTEX:079AC37B86327E725A17F4E24841B02966053B46
   |texte=   In situ FT-IR and kinetic study of methanol synthesis from CO2/H2 over ZnAl2O4 and Cu–ZnAl2O4 catalysts
}}