In situ FT-IR study of adsorbed species on a Cu-ZnAl2O4 methanol catalyst under 1 MPa pressure and at 525 K: Effect of the H2CO/CO2 feed stream composition

Article abstract of DOI:10.1016/0304-5102(89)80290-1

An IR cell which can be used as a continuous flow reactor up to 1 MPa and 525 K is described. Application to the methanol synthesis from CO + CO₂ + H₂ reaction on a 15% Cu-ZnAl₂O₄ catalyst shows that two different mechanisms of CH₃OH formation occur, depending on the gas feed composition. With no CO₂, ZnAl₂O₄ plays an important role and ZnAl₂O₄ bidentate formate and methoxy species are intermediate. In the CO₂ + H₂ case, the reaction principally occurs on the copper sites, with copper formate species as intermediate. The maximum activity composition (H₂:CO:CO₂ = 67:30:3) does not correspond to a maximum in the number of adsorbed species, whatever their nature.