Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin

Abstract

Vanillin is one of the most commonly used natural products, which can also be produced from lignin-derived feedstocks. The chemical synthesis of vanillin is well-established in large-scale production from petrochemical-based starting materials. To overcome this problem, lignin-derived monomers (such as eugenol, isoeugenol, ferulic acid etc.) have been effectively used in the past few years. However, selective and efficient production of vanillin from these feedstocks still remains an issue to replace the existing process. In this work, new transition metal-based catalysts were proposed to investigate their efficiency in vanillin production. Reduced graphene oxide supported Fe and Co catalysts showed high conversion of isoeugenol under mild reaction conditions using H2O2 as oxidizing agent. Fe catalysts were more selective as compared to Co catalysts, providing a 63% vanillin selectivity at 61% conversion in 2 h. The mechanochemical process was demonstrated as an effective approach to prepare supported metal catalysts that exhibited high activity for the production of vanillin from isoeugenol.

Continuous‐Flow Synthesis of Supported Magnetic Iron Oxide Nanoparticles for Efficient Isoeugenol Conversion into Vanillin

“…The increasing global demand of vanillin cannot be met anymore by the supply of vanilla orchid pods as the sole source . Only approximately 1 % of the global production of vanillin is derived from vanilla pods; the majority is produced synthetically by using, for example, lignin and (iso)eugenol as starting materials. The commercial value of vanillin extracted from vanilla pods varies between 1200–4000 USD kg −1 , excluding inflation .…”

“…[16] It can also be obtained from lignin fractionsthrough depolymerization and subsequentconversion and/or isolation.T he increasing globald emand of vanillin cannot be met anymore by the supply of vanilla orchid pods as the sole source. [17] Only approximately 1% of the globalp roduction of vanillin is derived from vanilla pods;t he majority is produced synthetically by using, for example, lignin [18] and (iso)eugenol [19] as starting materials.T he commercial value of vanillin extracted from vanilla pods varies between 1200-4000 USD kg À1 ,e xcluding inflation. [20] Although the oxidative disruption of isoeugenol( Scheme1)w as already reported, significant results were reported by Shimonie tal.…”

Mechanochemical Preparation of Novel Polysaccharide-Supported Nb2O5 Catalysts

“…Isoeugenol calibration was carried out in the 2.00-60.00 g L −1 range (r 2 0.98). The identification and resulting retention time of the products under the above conditions were eugenol (28 min), vanillin (30 min), diphenyl ether (31 min), isoeugenol (33 min) and calamenene oligomers (37 min) [45].…”

“…Pore size distribution (PSD) was calculated using the adsorption branch of the nitrogen adsorption-desorption isotherm and the Barret-Joyner-Halenda formula (BJH). The total pore volume, V BJH , was obtained from the PSD profiles [45].…”

Efficient Liquid‐Assisted Grinding Selective Aqueous Oxidation of Sulfides Using Supported Heteropolyacid Catalysts

“…[6] Mechanochemistry is to date widely exploited in a wide range of applications in different fields including down-stream processing for plants treatment, [7] mechanical pre-treatment of lignocellulosic biomass, [8] and pharmaceutical formulation preparation. [9] Additionally, mechanochemistry has been recently extended to the synthesis of metal complexes, [10] the production of catalysts and nanomaterials [11][12][13][14][15] and the formation of metal-organic frameworks. [16] Organic mechanochemical synthesis has also been gaining momentum in recent years considered an important and versatile tool for the sustainable production of target organic compounds.…”