abstract
This study presents a stable, selective and reusable catalyst prepared by a biomass-derived acid-biochar (acid-char) functionalized with the organometallic complex [Mol(2)(CO)(3)(MeCN)(2)] (Mo), yielding a material where the [Mol(2)(CO)(3)] core is coordinated at surface functional groups of the acid-char material. The characterization of this catalyst, denoted as Mo@acid-char, by using various complementary techniques confirmed the successful immobilization of the [Mol(2)(CO)(3)] core at the surface of the acid-char material. The catalytic activity of the material was evaluated for olefin epoxidation reactions of cis-cyclooctene and R-(+)-limonene, varying relevant reaction parameters such as temperature, solvent and oxidant ratio. The Mo@acid-char showed an excellent selectivity for epoxide products at mild temperature (ca. 328 K). Interestingly, the catalyst exhibited its highest activity when the reaction was carried out under solventless conditions, allowing the catalysts reuse for several cycles. Thus, the synthesized Mo@acid-char contributed for a sustainable use of biomass waste (e.g., sisal) through the development of environmentally friendly processes avoiding the use of solvents.
keywords
COMPLEXES; OXIDATION; MOLYBDENUM(II); STRATEGIES; HYDROCHARS; BIOMASS; MO(II)
subject category
Chemistry
authors
Petit, C; Silva, MV; Mestre, AS; Ania, CO; Vaz, PD; Carvalho, AP; Nunes, CD
our authors
Pedro Miguel Duarte Vaz
Collaboratoracknowledgements
Fundacao para a Ciencia e Tecnologia (FCT), Portugal, is acknowledged for financial support (PEst-OE/QUI/UI0612/2013). ASM thanks the financial support of FCT for the Post-doc grant SFRH/BPD/86693/2012. G09 calculations were made possible due to the computing resources provided by STFC Scientific Computing Department's SCARF cluster. Authors also thank Cordex for supplying the sisal residues.