Experimental Design for Modeling and Multi‐response Optimization of Catalytic Cyclohexene Epoxidation over Polyoxometalates

Abstract

An experimental design methodology was applied to optimize cyclohexene epoxidation with hydrogen peroxide in the presence of acid‐activated montmorillonite clay supported on 11‐molybdovanado‐phosphoric acid, with the Keggin structure H4[PVMo11O40] · 13H2O (PVMo) as catalyst. The statistical study of the process was achieved through a two‐level, full‐factorial experimental design with five process parameters. The significant input variables (key factors) that influenced the performance of cyclohexene oxidation are the catalyst weight, catalyst loading, temperature, H2O2 concentration, and the reaction time. The effect of the individual parameters and their interaction effects on the cyclohexene conversion, as well as the selectivity of cyclohexane‐1,2‐diol, was determined, and a statistical model of the process was developed. The process was optimized by considering the two responses simultaneously, which allows defining the optimal regions for the significant process variables. The optimal conditions were obtained for the catalyst weight of 0.05 g, temperature of 70°C, and reaction time of 9 h, with 20% PVMo as the active phase and hydrogen peroxide as oxidant.

Recent Progress in Application of Molybdenum-Based Catalysts for Epoxidation of Alkenes

“…Interest has been paid in homogeneous and heterogeneous systems by making full use of the catalytic activity of polyoxometalates (POMs) in distinct oxidation processes. These superior applications may result from their unique properties, such as acid/base characterization, fast and reversible multi-electron redox transformations even under mild conditions, electron-transfer properties, thermal and oxidative strength, flexibility by the incorporation of appropriate metal ions or counterions to endow a superior catalytic performance [39,40].…”

“…[46,47]. Boudjema et al [40] supported 11-molybdovanado-phosphoric acid with the Keggin structure H 4 [PVMo 11 O 40 ]•13H 2 O (PVMo) on acid-activated montmorillonite clay to optimize cyclohexene epoxidation with hydrogen peroxide. Jameel et al [48] have used chloropropyltriethoxysilane functionalized SBA-15 as a support for immobilization of Na 9 PMo 11 O 39 (PMo 11 ) and gold nanoparticles and studied the molecular oxygen reactivity and stability under facial reaction conditions.…”

Recent advances in the utilization of glycerol for the production of lactic acid by catalysis

“…Owing to the variable compositions, adjustable properties and suitable oxidation-reduction properties, POMs can meet the requirements of specific catalytic processes. 48,49 In the absence of bases, conversion of glycerol into lactic acid requires a bifunctional catalyst with both Lewis acid and redox capabilities. In view of this, Tao et al 31 50 for the oxidation of glycerol to lactic acid.…”

“…Among them, POMs with Mo or W as additional elements have been typical and widely used. Owing to the variable compositions, adjustable properties and suitable oxidation–reduction properties, POMs can meet the requirements of specific catalytic processes 48,49 …”

Response surface methodology optimization of supramolecular dispersive liquid‐liquid microextraction‐solidified floating organic drop of brilliant green and its spectrophotometric determination

“…[41] The significance of the quadratic equation is also determined by the values of R 2 and R 2 adj , the closeness of these values to one indicates the high correlation between the experimental and the predicted results. [42] The fitting of model predicted values with experimental residual were evaluated by R 2 (0.9992) and R 2 adj (0.9987) values. [43] The plot of predicted values against the experimental values is a 45 straight line (Figure 3) which further confirms the suitability of the model.…”