Platinum Supported on [60]Fullerene-Grafted Silica as a New Potential Catalyst for Hydrogenation

• Published in: Journal of catalysis 1998-06, Vol.176 (2), p.358-364
• Main Authors: Coq, Bernard, Brotons, Valérie, Planeix, Jean Marc, de Ménorval, Louis Charles, Dutartre, Roger
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts: preparations and properties; Chemical Sciences; Chemistry; Exact sciences and technology; General and physical chemistry; Material chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1006/jcat.1998.2040

A Pt-based catalyst supported on a silica grafted with [60]full-erene was prepared and evaluated in the liquid-phase hydrogenation of cinnamaldehyde. Silanization of a large-pore silica was carried out with diethoxymethylsilane. [60]Fullerene was anchored on the modified silica through a hydrosilylation reaction with Si–H bonds, mediated by a Pt0Karsted catalyst. IR,29Si and13C MAS NMR spectroscopies, and N2adsorption–desorption provided evidence that [60]fullerene was covalently bonded onto the silica surface. [60]Fullerene was released at ca 950, 750, and 800 K in He, air, and H2, respectively, even in the presence of 0.8 wt% Pt. The very high density of [60]fullerene grafting confers a strong hydrophobic character to the surface. A fairly good selectivity to cinnamyl alcohol was observed on this catalyst at cinnamaldehyde conversion above 90%. This behavior might be better explained by a specific interaction between the phenyl ring of cinnamaldehyde and the grafted [60]fullerene film than by a modification of the Pt d-band. The IR spectroscopy of adsorbed CO did not provide any evidence of an enhanced, or reduced, back-donation to 2π* antibonding orbitals of CO, with respect to classical supported Pt catalysts.