Catalytic Oxidation of Vanillyl Alcohol Using FeMCM-41 Nanoporous Tubular Reactor

Abstract

Iron containing nanoporous MCM-41 (FeMCM-41) with different Si/Fe ratios of 50, 100 and 150 was synthesized by hydrothermal synthesis process. The materials obtained from hydrothermal synthesis were characterized by various physico chemical techniques such as XRD, N2 adsorption, DR UV-vis, EPR and FTIR spectroscopy. XRD analyses of FeMCM-41 materials confirmed the presence of well-ordered crystalline structure. N2 isotherm of FeMCM-41 materials showed type IV adsorption isotherm. EPR and DR UV-vis analysis of FeMCM-41 samples indicates the presence of high tetrahedral coordination at the Si/Fe ratios of 100 and 150. The catalytic performance of FeMCM-41 nano tubular reactor was tested in the liquid phase oxidation of vanillyl alcohol into vanillin using H2O2 (50[Formula: see text]wt% in water). The reaction products were analyzed by gas chromatography in DB-5 capillary column with flame ionization detector. The products were confirmed by 1H NMR, [Formula: see text]C NMR and LC-Mass spectroscopy. The maximum conversion of vanillyl alcohol (85%) and selectivity towards vanillin (82%) were observed using the catalyst FeMCM-41(100) in 30[Formula: see text]min at 60[Formula: see text]C. The influence of reaction temperature, reaction time, reactants molar ratio, Si/Fe ratio and amount of catalyst were investigated.

Oxidant-free and metal-free highly-selective catalytic production of vanillic aldehyde through activated carbon fiber-mediated aerobic oxidation

“…Next, it would be also necessary to investigate if heating combined with oxidants would convert VLA to VAE. Since H2O2 is the most typical oxidant for conversion of VLA [7,11], H2O2 was then adopted here for VLA conversion. When H2O2 was combined with oven heating, a noticeably amount of VLA was converted (~15.8%), and, a notable amount of VAE was detected (~9.2%), demonstrating that the presence of oxidant could oxidize VLA and transform it to VAE.…”

“…Biomass represent a key renewable source consisting of lignocellulosic substances, which can be depolymerized to generate various bio-derivatives [1][2][3][4][5]. Upgrading biomass derivatives to fuels and chemicals is an advantageous approach for transferring biomass to value-added products.…”

“…As conversion of VLA to VAE necessitates a particular oxidation of the alcohol group of VLA to an aldehyde group, it would be essential to establish a highly-selective oxidation process for converting VLA to VAE. Nowadays, the most traditional process for oxidation of VAL to VAE would be implemented by using oxidizing agents, such as H2O2 [7][8][9][10]. Nonetheless, the stoichiometric oxidation of alcohol of VLA to VAE by H2O2 would necessitate a large amount of H2O2.…”

“…Nonetheless, the stoichiometric oxidation of alcohol of VLA to VAE by H2O2 would necessitate a large amount of H2O2. Besides, metal catalysts, and other energy inputs (e.g., light, ultrasound and heat) are also demanded for improving VLA oxidation by H2O2 [7][8][9][10][11]. Nonetheless, conversion efficiencies of VLA to VAE by H2O2-involved techniques typically afford low conversion efficiencies and low selectivities because of over-oxidation of VLA or even decomposition of VLA [8,10,12,13].…”

Base metal iron catalyzed sustainable oxidation of vanillyl alcohol to vanillic acid in deep eutectic solvents and implementation of vanillic acid for fine-chemical synthesis

“…In a process of targeted oxidation of vanillyl alcohol to vanillin, vanillic acid has oen been found as an over-oxidation product. [18][19][20][21][22][23][24][25] There are few reports for the selective oxidation of vanillyl alcohol or vanillin to vanillic acid. In a very old report, a stoichiometric amount of silver oxide (in situ generated from AgNO 3 and NaOH) was used as an oxidant to convert vanillin to vanillic acid.…”