Tuning the Metal-Support Interaction by Structural Recognition of Cobalt-Based Catalyst Precursors

• Published in: Angewandte Chemie International Edition Vol. 54; no. 23; pp. 6824 - 6827
• Main Authors: Larmier, Kim, Chizallet, Céline, Raybaud, Pascal
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.06.2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: adsorption; catalyst preparation; Catalysts; Cobalt; density functional calculations; Mathematical models; Precipitates; Precipitation; Precursors; Recognition; Silica; Synthesis; Tuning; γ-alumina; catalyst preparation; γ-alumina; density functional calculations; adsorption; cobalt
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201502069

Controlling the nature and size of cobalt(II) polynuclear precursors on γ‐alumina and silica‐alumina supports represents a challenge for the synthesis of optimal cobalt‐based heterogeneous catalysts. By density functional theory (DFT) calculations, we show how after drying the interaction of cobalt(II) precursor on γ‐alumina is driven by a structural recognition phenomenon, leading to the formation of an epitaxial Co(OH)2 precipitate involving a Co–Al hydrotalcite‐like interface. On a silica‐alumina surface, this phenomenon is prevented due to the passivation effect of silica domains. This finding opens new routes to tune the metal–support interaction at the synthesis step of heterogeneous catalysts. The interaction of cobalt‐based catalyst precursors with γ‐alumina and amorphous silica–alumina surfaces was investigated by means of DFT calculations. A structural recognition between the surface and the precursor could be evidenced. A model for the growth of the experimentally observed β‐Co(OH)2 on the surface could be proposed from those calculations.