Mechanistic Study of Carbon Dioxide Hydrogenation over Pd/ZnO-Based Catalysts: The Role of Palladium–Zinc Alloy in Selective Methanol Synthesis
- Journal Article
Rights / licenseCreative Commons Attribution 4.0 International
Pd/ZnO catalysts show good activity and high selectivity to methanol during catalytic CO2 hydrogenation. The Pd-Zn alloy phase has usually been considered as the active phase, though mechanistic studies under operando conditions have not been conducted to verify this. Here, we report a mechanistic study under realistic conditions of methanol synthesis, using in situ and operando X-ray absorption spectroscopy, X-ray powder diffraction, and time-resolved isotope labeling experiments coupled with FTIR spectroscopy and mass spectrometry. Pd-Zn alloy-based catalysts, prepared through reduction of a heterobimetallic PdIIZnII acetate bridge complex, and which do not contain zinc oxide or any PdZn/ZnO interface, produce mostly CO. The Pd-Zn phase is associated with the formation of CO, and does not provide the active sites required to produce methanol from the direct hydrogenation of carbon dioxide. The presence of a ZnO phase, in contact with a Pd-Zn phase, is essential for efficient methanol production. Show more
Journal / seriesAngewandte Chemie. International Edition
Pages / Article No.
SubjectCO2 hydrogenation; isotope labeling; methanol; operando XAS; PdZn alloy
Organisational unit03746 - Van Bokhoven, Jeroen A. / Van Bokhoven, Jeroen A.
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