In this article, the biocatalytic oxidation of ethanol into acetaldehyde was studied using a catalase entrapped within a monolithic polyampholyte cryogel, p(APTAC-co-AMPS), as catalyst. When an anionic monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS), was mixed with a cationic monomer, (3-acrylamidopropyl) trimethylammonium chloride (APTAC), under cryo-polymerization conditions at a molar ratio of monomers [APTAC]:[AMPS] = 75:25 mol.% in the presence of 10 mol.% cross-linking agent, N,N-methylenebisacrylamide (MBAA), the macroporous polyampholyte cryogels containing various amounts of catalase were synthesized in situ. The conversion of ethanol into acetaldehyde in good-to-high yields was observed in flow-through and batch-type reactors under optimal conditions: at T = 10–20 °C, pH = 6.9–7.1, [C₂H₅OH]:[H₂O₂] = 50:50 vol.%. According to the SEM images, the pore sizes of the p(AMPS-co-APTAC) cryogel vary from 15 to 55 μm. The catalytic activity of catalase entrapped within a monolithic polyampholyte cryogel in the conversion of ethanol into acetaldehyde was evaluated through the determination of kinetic parameters such as the Michaelis constant (K_m), maximum enzymatic rate (V_max), activation energy (E_a), turnover number (TON) and turnover frequency (TOF). The catalase encapsulated within the monolithic polyampholyte cryogel exhibits a high conversion of ethanol into acetaldehyde. The key parameters of ethanol oxidation in flow and batch reactors in the presence of the cryogel monolith were calculated.

In this article, the biocatalytic oxidation of ethanol into acetaldehyde was studied using a catalase entrapped within monolithic polyampholyte cryogel, p(APTAC-co-AMPS), derived from an anionic monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS), and a cationic monomer, (3-acrylamidopropyl) trimethylammonium chloride (APTAC) as catalyst. Macroporous polyampholyte cryogels containing various amounts of catalase were synthesized in situ under cryo-polymerization conditions at a molar ratio of monomers [APTAC]:[AMPS] = 75:25 mol.% in the presence of 10 mol.% cross-linking agent, N,N-methylenebisacrylamide (MBAA). The conversion of ethanol into acetaldehyde in good-to-high yields was observed in flow-through and batch type reactors under optimal conditions: at T = 10-20 C, pH = 7.1, [C2H5OH]:[H2O2] = 50:50 vol.%. According to SEM image the pore sizes of p(AMPS-co-APTAC) cryogel vary from 15 to 55 μm. The catalytic activity of catalase entrapped within monolithic polyampholyte cryogel in the conversion of ethanol into acetaldehyde was evaluated through the determination of such kinetic parameters as Michaelis constant (Km), the maximum enzymatic rate (Vmax), activation energy (Ea), turnover number (TON) and turnover frequency (TOF). The catalase encapsulated within monolithic polyampholyte cryogel exhibits a high conversion of ethanol into acetaldehyde. The advantages and disadvantages of flow-through and batch type reactors were highlighted.

In this work we obtained a polymer-metal complex by mixing aqueous solution of copper(II) acetate with PVA at a certain ratio, pH of the solution and temperature. The composition of the complex compound was determined by potentiometric and conductometric titration. The possibility of a complex formation was proved by calculating thermodynamic characteristics. The stability constant of the polymer-metal complex was calculated on the basis of the modified Bjerrum’s method. The metal-polymer complex was synthesized in the ratio 1:2. IR spectroscopy and scanning electron microscopy (SEM) confirmed the coordination of polymeric PVA ligand to copper and allowed evaluating the morphology and features of the complex surface. The catalytic activity of the synthesized compound was evaluated in the oxidation reaction of elemental phosphorus (P4) by oxygen in aqueous-organic media under mild conditions. Quantitative analysis of phosphoric acid was made by photocolorimetric method. We found that the oxidation process of P4 in the presence of the complex Cu(PVA)2(OAc)2 in aqueous-organic media is characterized with the maximum absorption rate, in comparison with Cu(OAc)2·H2O oxidation process with P4, and yields up to 97% of the products. The process of oxidation of yellow phosphorus by oxygen in the presence of the copper(II)-PVA complex proceeds through key reactions of two-electron reduction of the catalyst P4 with the formation of intermediate phosphorus-containing products P3+ and the stages of catalyst regeneration by oxygen. Twenty-electron oxidation of P4 to the phosphorus-containing P5+ products involves 10 two-electron redox reactions and a number of complexation or hydrolysis stages.

The aqueous solution of copper (II) complex of poly(vinyl alcohol) (PVA-Cu(II)) was characterized by conductimetric titration, UV-Vis spectroscopy and FTIR. The molar composition of the PVA-Cu(II) complex was determined to be equimolar. Subsequently, the PVA-Cu(II) complex was reduced by sodium borohydride to prepare copper nanoparticles (CuNPs) stabilized by PVA (PVA-CuNPs). According to DLS measurements in aqueous solution the average size of PVA-CuNPs was varied from 10 to 25 nm depending on the amount of sodium borohydride used for reduction. The optimal volume of sodium borohydride to obtain 96 % PVA-CuNPs with 10 nm size was found to be 3 mL of NaBH4 (0.5 mol×L–1). The PVA-CuNPs were then deposited onto SiO2 support to obtain SiO2/PVA-CuNPs nanocatalyst for the oxidation of 1-propanol. The SEM image and XRD spectrum of SiO2/PVA-CuNPs nanocatalyst showed the deposition of PVA-CuNPs on the surface of SiO2. The resulting SiO2/PVA-CuNPs nanocatalyst was used for the oxidation of 1-propanol to propionaldehyde by molecular oxygen in a batch-type catalytic reactor at 20oС and atmospheric pressure. The optimum catalyst mass and reaction time were found for the conversion of 1-propanol to propionaldehyde with yields ranging from 61.4 % to 87.8 %. Criteria of hydrodynamic similarity (Re, Pr’, Sh), overall volumetric mass transfer coefficient (), and economic metric (STY) were evaluated. 1-Propanol reacted with the decomposed atomically adsorbed oxygen atoms on the Cu(111), (220) surfaces to form propionaldehyde and water.

In this work, we obtained complexes by mixing aqueous solution of palladium(II) chloride with polyvinylpyrrolidone and polyethylene glycol. The composition of the complex compounds was determined by potentiometric and conductometric titration. IR spectroscopy and scanning electron microscopy (SEM) confirmed the coordination of polymeric ligand to palladium and allowed evaluating the morphology and features of the complex surface. The catalytic activity of the synthesized compounds in the oxidation of octene-1 by inorganic oxidizers (NaBrO3, K2S2O8) in aqueous-organic media in dimethyl sulfoxide (DMSO) under mild conditions was calculated. The reaction product was octanone-2, obtained in good yield (62–98%). Quantitative analysis of octanone-2 was made by the gas-chromatographic method. Mass spectrometry confirms the formation of octanone-2. The complexes are able to participate in five consecutive catalytic cycles without significant loss of catalytic efficiency. Oxidation of octene-1 proceeds by the oxidation-reduction mechanism and consists of two key stages.