High Performance Pd,PdNi, PdSn and PdSnNi Nanocatalysts Supported on Carbon Nanotubes for Electrooxidation of C2C4 Alcohols

Nanocatalysts Pd, Pd₈Ni₂, Pd₈Sn₂ and Pd₈Sn₁Ni₁ supported on multi‐walled carbon nanotubes (MWCNTs) were successively synthesized by the chemical reduction method in the glycol‐water mixture solvent. Transmission electron microscopy results show that the prepared Pd, Pd₈Ni₂, Pd₈Sn₂ and Pd₈Sn₁Ni₁ nanoparticles are uniformly dispersed on the surface of MWCNTs. The average particle sizes of the nanocatalysts are 3.5–3.8 nm. Electroactivity of the prepared catalysts towards oxidation of ethanol, 1‐propanol, 2‐propanol, n‐butanol, iso‐butanol and sec‐butanol (C2? C4 alcohols) in alkaline medium was studied by cyclic voltammetry and chronoamperometry. The current density obtained for the electrooxidation of C2? C4 alcohols depends on the catalysts and the various structures of the alcohols. Addition of Sn or/and Ni to Pd nanoparticles enhances the electroactivity of the Pd/MWCNT catalyst. Furthermore, the ternary Pd₈Sn₁Ni₁/MWCNT catalyst presents the highest electroactivity for the oxidation of C2? C4 alcohols among the prepared catalysts. Electrocatalytic activity order among propanol isomers and butanol isomers is as follows respectively: 1‐propanol > 2‐propanol, and n‐butanol > iso‐butanol > sec‐butanol > tert‐butanol. This is consistent with the Mulliken charge value of the carbon atom bonded with hydroxyl group in the corresponding alcohol molecule.     

Spectrophotometric Determination of Water Content in Alcohol Organic Solvents

In this work, the absorption spectral characteristics and color‐change reaction mechanism of cobalt(II) chloride(CoCl₂) in alcohol organic solvents has been investigated in the presence of water, and then the optimum conditions for determining the water content in the solvents were selected. Results indicated that the absorption spectra of CoCl₂ in alcohols decreased with the increment of water content. At the maximum absorption wavelength of 656 nm, there were good linear relationships between the logarithm of the absorbance and the water content in organic solvents such as ethanol, n‐propanol, iso‐propanol and n‐butanol with related coefficients in the range of 0.9996?0.9998. For determining water content in organic solvents, this method is simple, rapid, sensitive, reproducible and environmentally friendly. Furthermore, the linear range cannot restrict determination of the water content in organic solvents. This method had been applied to determine the water content in ethanol and n‐butanol with satisfactory recovery of water in n‐butanol between 98.41%?101.29%.     

Effects of Short‐Chain Alcohol on the Micellization of Gemini Surfactant C16‐6‐16 · 2Br in Aqueous Solution

The effects of ethanol, n‐butanol, and n‐hexanol on the micellization of cationic Gemini surfactant C16‐6‐16 · 2Br have been investigated using conductance and steady fluorescence measurements. The results show that the critical micelle concentration (CMC) increases with the addition of ethanol, but decreases with n‐butano1 or n‐hexanol. With the addition of the above alcohols, both the micelle ionization degree and the mole fraction of alcohol in the micelle increase, however, the micelle aggregation number decreases at a fixed concentration of surfactant. When given a special concentration of alcohol, the micelle aggregation number increases as the increase of the surfactant concentration.     

Enantiomer Separation of α—Dimethyl Dicarboxylate Biphenyl and Related Biphenyl Compounds by Normal Phase HPLC on Polysaccharide Based Chiral Stationary Phases

Cellulose tris(4-methylphenylcarbamate),amylose tris(3,5-dimethylphenylcarbamate) and amylose tris (phenylcarbamate) were prepared by the method reported by Okamoto and were coated onto an aminopropylated mesoporous spherical silica gel.These final products were used as chiral stationary phases of high performance liquid chromatography for the eighteen structurally related biphenyl compounds.The resolution was made using normal-phase methodology with a mobile phase consisting of n-hexane-alcohol(ethanol,1-propanol,2-propanol or 1-butanol).The effects of various aliphatic alcohols in the mobile phase were studied.The structural features of the solutes that influence their k′ were discussed.A dominant effects of trifluoroacetic acid on chiral separation of acidic solutes was noted.     

Alcohol‐Vapor Inclusion in Single‐Crystal Adsorbents [MII2(bza)4(pyz)]n (M=Rh,Cu): Structural Study and Application to Separation Membranes

The vapor absorbency of the series of alcohols methanol, ethanol, 1‐propanol, 1‐butanol, and 1‐pentanol was characterized on the single‐crystal adsorbents [M^II₂(bza)₄(pyz)]_n (bza=benzoate, pyz=pyrazine, M=Rh ( 1 ), Cu ( 2 )). The crystal structures of all the alcohol inclusions were determined by single‐crystal X‐ray crystallography at 90 K. The crystal‐phase transition induced by guest adsorption occurred in the inclusion crystals except for 1‐propanol. A hydrogen‐bonded dimer of adsorbed alcohol was found in the methanol‐ and ethanol‐inclusion crystals, which is similar to a previous observation in 2 ?2EtOH (S. Takamizawa, T. Saito, T. Akatsuka, E. Nakata, Inorg. Chem. 2005 , 44, 1421–1424). In contrast, an isolated monomer was present in the channel for 1‐propanol, 1‐butanol, and 1‐pentanol inclusions. All adsorbed alcohols were stabilized by hydrophilic and/or hydrophobic interactions between host and guest. From the combined results of microscopic determination (crystal structure) and macroscopic observation (gas‐adsorption property), the observed transition induced by gas adsorption is explained by stepwise inclusion into the individual cavities, which is called the “step‐loading effect.” Alcohol/water separation was attempted by a pervaporation technique with microcrystals of 2 dispersed in a poly(dimethylsiloxane) membrane. In the alcohol/water separation, the membrane showed effective separation ability and gave separation factors (alcohol/water) of 5.6 and 4.7 for methanol and ethanol at room temperature, respectively.     

Study on Vapor-Liquid Nucleation Rates for n-Alcohols by Density Functional Theory

The statistical associating fluid theory (SAFT) in conjunction with the Weeks‐Chandler‐Anderson (WCA) approximation for intermolecular interaction is employed to construct a non‐uniform equation of state (EOS) for n‐alcohols. The molecular parameters for methanol, ethanol, 1‐propanol, 1‐butanol, 1‐pentanol and 1‐hexanol are obtained by fitting to the experimental data of vapor‐liquid equilibria and then used to predict the nucleation rates under the framework of density functional theory (DFT). The predictions are found to be in quite good agreement with the experimental data. Investigation shows that the combination of DFT and SAFT is a successful approach for vapor‐liquid nucleation rates of n‐alcohols.     

Effects of alcohols on micellization and on the reaction methyl 4‐nitrobenzenesulfonate + Br− in cetyltrimethylammonium bromide aqueous micellar solutions

The effects of n‐hexanol, n‐pentanol, and n‐butanol on the critical micelle concentration (cmc), on the micellar ionization degree (α), and on the rate of the reaction methyl 4‐nitrobenzenesulfonate + Br^? have been investigated in cetyltrimethylammonium bromide (CTAB) aqueous solutions. An increase in the alcohol concentration present in the solution produces a decrease in the cmc and an increase in the micellar ionization degree. Kinetic data show that the observed rate constant decreases as alcohol concentration increases. This result was rationalized by considering variations in the equilibrium binding constant of the methyl 4‐nitrobenzenesulfonate molecules to the micelles, variations in the interfacial bromide ion concentration, and variations in the characteristics of the water–alcohol bulk phase provoked by the presence of alcohols. When these operative factors are considered, kinetic data in this and other works show that the second‐order rate constants in the micellar pseudophases of water–alcohol micellar solutions are quite similar to those estimated in the absence of alcohols. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 634–641, 2004     

Synthesis of 2‐Phenylquinoline and its Derivatives by Multicomponent Reaction of Aniline,Benzylamine, Alcohols,and CCl4 Catalyzed by FeCl3·6H2O

2‐Phenylquinolines, 2‐phenyl‐3‐methyl‐quinolines, and 2‐phenyl‐3‐ethylquinolines were synthesized in high yields (78–90%) by the reaction of aniline, benzylamine, aliphatic alcohols (ethanol, n‐propanol, n‐butanol), and CCl₄ catalyzed by FeCl₃·6H₂O in tetrachloromethane.     

Excess Molar Volumes and Viscosities for Binary Mixtures of 1-Alkoxypropan-2-ols with 1-Butanol, and 2-Butanol at 298.15 K and Atmospheric Pressure

Excess molar volumes Vm^E and kinematic viscosities v have been measured as a function of composition for binary mixtures of propylene glycol monomethyl ether （1-methoxy-2-propanol）, MeOCH2CH（OH）Me, propylene glycol monoethyl ether （1-ethoxy-2-propanol）, EtOCH2CH（OH）Me, propylene glycol monopropyl ether （1-propoxy-2-propanol）, PrOCH2CH（OH）Me, propylene glycol monobutyl ether （1-butoxy-2-propanol）, BuOCH2CH（OH）Me, and propylene glycol tert-butyl ether （1-tert-butoxy-2-propanol）, t-BuOCH2CH（OH）Me with 1-butanol, and 2-butanol, at 298.15 K and atmospheric pressure. The excess molar volumes are negative across the entire range of composition for all the systems with 1-butanol, and positive for the systems 2-butanol＋ 1-methoxy-2-propanol, and ＋1-propoxy-2-propanol, negative for the systems 2-butanol＋1-butoxy-2-propanol, and change sign for the systems 2-butanol＋ 1-ethoxy-2-propanol, and ＋ 1-tert-butoxy-2-propanol. From the experimental data, the deviation in dynamic viscosity η from ∑χiηi has been calculated. Both excess molar volumes and viscosity deviations have been correlated using a Redlich-Kister type polynomial equation by the method of least-squares for the estimation of the binary coefficients and the standard errors.     

Phenylsulfonic Acid Functionalized Mesoporous Silica Catalyzed Transetherification of Alcohols with Dimethoxymethane

Phenylsulfonic acid functionalized mesoporous silica was synthesized by condensation of tetraethylorthosilicate with phenyltrimethoxysilane, and then sulfonation using 30% fuming sulfuric acid. The material was characterized using FT‐IR, DSC, XPS, TEM and N2 adsorption/desorption measurements. DSC revealed that sulfonic acid group of the catalyst was decomposed at 354.8°C, indicating that the catalyst exhibited high thermal stability. XPS showed that there existed three kinds of different silicon species on surface of the catalyst. The catalytic performance of the catalyst was evaluated using transetherification of alcohols with dimethoxymethane. It was found that among primary alcohols, the selectivities of the two long‐chain alcohols for n‐dedocanol and n‐tetradecyl alcohol were higher than 97.0% at the conversions of 43.6% and 65.3%, respectively, while the selectivities of the short‐chain alcohols except for n‐hexanol were less than 90.0% at the conversions of over 80.0%. Due to steric barrier, the secondary alcohols such as iso‐butanol and cyclohexanol afforded conversions of 79.4% and 60.5%, and the selectivities of the two alcohols were more than 90.0%. The sequence in conversion of the substituted phenols is as follows: p‐nitrophenol>p‐fluorophenol≥p‐bromophenol>p‐cresol>m‐cresol.     

A kinetic method to estimate dissociation degrees of micellar aggregates in TTAB–alcohol aqueous micellar solutions

The reactions of dehydrochlorination of 1,1‐trichloro‐2,2‐bis(p‐chlorophenyl)ethane, DDT, and 1,1‐dichloro‐2,2‐bis(p‐chlorophenyl)ethane, DDD, with hydroxide ions were studied in various TTAB–alcohol (TTAB = tetradecyltrimethylammonium bromide) aqueous micellar solutions as a function of alcohol content. The alcohols used were heptanol, hexanol, pentanol, butanol, isobutanol, tert butanol, propanol and isopropanol. Kinetic data show that the dissociation degree of the micelles is the main factor controlling reactivity in all the TTAB–alcohol micellar solutions. This fact permits the development of a kinetic method in order to estimate the dissociation degree of the micellar aggregates present in the alcohol–TTAB aqueous micellar solutions. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 204–209, 2000     

Highly Efficient Direct Aerobic Oxidative Esterification of Cinnamyl Alcohol with Alkyl Alcohols Catalysed by Gold Nanoparticles Incarcerated in a Nanoporous Polymer Matrix: A Tool for Investigating the Role of the Polymer Host

The selective aerobic oxidation of cinnamyl alcohol to cinnamaldehyde, as well as direct oxidative esterification of this alcohol with primary and secondary aliphatic alcohols, were achieved with high chemoselectivity by using gold nanoparticles supported in a nanoporous semicrystalline multi‐block copolymer matrix, which consisted of syndiotactic polystyrene‐co‐cis‐1,4‐polybutadiene. The cascade reaction that leads to the alkyl cinnamates occurs through two oxidation steps: the selective oxidation of cinnamyl alcohol to cinnamaldehyde, followed by oxidation of the hemiacetal that results from the base‐catalysed reaction of cinnamaldehyde with an aliphatic alcohol. The rate constants for the two steps were evaluated in the temperature range 10–45 °C. The cinnamyl alcohol oxidation is faster than the oxidative esterification of cinnamaldehyde with methanol, ethanol, 2‐propanol, 1‐butanol, 1‐hexanol or 1‐octanol. The rate constants of the latter reaction are pseudo‐zero order with respect to the aliphatic alcohol and decrease as the bulkiness of the alcohol is increased. The activation energy (E_a) for the two oxidation steps was calculated for esterification of cinnamyl alcohol with 1‐butanol (E_a=57.8±11.5 and 62.7±16.7 kJ mol^?1 for the first and second step, respectively). The oxidative esterification of cinnamyl alcohol with 2‐phenylethanol follows pseudo‐first‐order kinetics with respect to 2‐phenylethanol and is faster than observed for other alcohols because of fast diffusion of the aromatic alcohol in the crystalline phase of the support. The kinetic investigation allowed us to assess the role of the polymer support in the determination of both high activity and selectivity in the title reaction.     

Amperometric Response of Alcohols Dissolved in High Resistance Hydrocarbon Media at Microelectrodes Without Supporting Electrolyte

Narrow‐gap cells were fabricated for direct amperometric measurement of alcohol content in liquid hydrocarbon mixtures. Their performance has been investigated using methanol, ethanol, n‐propanol as sample components (ethanol was in most details studied). One type of the insulating materials was applied in order to obtain two copper discs. The surfaces of the copper microdiscs were covered with a Cu_xS modifying layer. The other cell constructed in the similar way had a carbon disc working electrode (with diameter of 30 µm and copper reference/counter electrode 0.3 mm). The amperometric behaviour of the alcohols have been investigated in toluene and n‐heptane solvents without background electrolyte. The amperometric current was found proportional to the ethanol concentration in the investigated range of 0.5–11 v/v%. The sensor’s performance was also tested with ethanol containing fuel products from a gas station.     

Stereospecific radical polymerization of N‐tert‐butoxycarbonylacrylamide in the presence of fluorinated alcohols

Radical polymerization of N‐tert‐butoxycarbonylacrylamide (NBocAAm) in toluene at low temperatures in the presence of the fluorinated alcohols, 2,2,2‐trifluoroethanol, 1,1,1,3,3,3‐hexafluoro‐2‐propanol, and nonafluoro‐tert‐butanol, afforded atactic, heterotactic, and syndiotactic polymers, respectively. NMR analysis revealed that the fluorinated alcohols formed hydrogen bonding‐assisted complexes with NBocAAm, with different structures. The difference in the structures of the complexes was responsible for the differences in the induced stereospecificities. Based on the structures of the complexes between NBocAAm and the fluorinated alcohols, mechanisms for the three kinds of stereospecific radical polymerizations are proposed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Selective swelling induced pore generation of amphiphilic block copolymers: The role of swelling agents

Swelling of block copolymers by selective solvents has emerged as an extremely simple and efficient process to produce nanoporous materials with well‐controlled porosities. However, the role of the swelling agents in this pore‐making process remains to be elucidated. Here we investigate the evolution of morphology, thickness, and surface chemistry of thin films of polystyrene‐block‐poly (2‐vinyl pyridine) (PS‐b‐P2VP) soaked in a series of alcohols with changing carbon atoms and hydroxyl groups in their molecules. It is found that, in addition to a strong affinity to the dispersed P2VP microdomains, the swelling agents should also have a moderate swelling effect to PS to allow appropriate plastic deformation of the PS matrix. Monohydric alcohols with longer aliphatic chains exhibit stronger ability to induce the pore formation and a remarkable increase in film thickness is associated with the pore formation. High‐carbon alcohols including n‐propanol, n‐butanol, and n‐hexanol produce cylindrical micelles upon prolonged exposure for their strong affinity toward the PS matrix. In contrast, methanol and polyhydric alcohols including glycol and glycerol show very limited effect to swell the copolymer films as their affinity to the PS matrix is low; however, they also evidently induce the surface segregation of P2VP blocks. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 926–933     

Mechanistic Study on Oxorhenium‐Catalyzed Deoxydehydration and Allylic Alcohol Isomerization

The reaction mechanism of 1,2×n‐deoxydehydration (DODH; n=1, 2, 3 …) reactions with 1‐butanol as a reductant in the presence of methyltrioxorhenium(VII) catalyst has been investigated by DFT. The reduced rhenium compound, methyloxodihydroxyrhenium(V), serves as the catalytically relevant species in both allylic alcohol isomerization and subsequent DODH processes. Compared with three‐step pathway A, involving [1,3]‐transposition of allylic alcohols, direct two‐step pathway B is an alternative option with lower activation barriers. The rate‐limiting step of the DODH reaction is the first hydrogen transfer in methyltrioxorhenium(VII) reduction. Moreover, the increase in the distance between two hydroxyl groups in direct 1,2×n‐DODH reactions for C4 and C6 diols results in a higher barrier height.     

Revisiting the Reactions of t‐BuX (X = Br,I) with Monoalcohols: A Mechanistic Analysis through Numerical Integration and Nonlinear Regression Methods

The reactions of two tertiary butyl halides, i.e., t‐ BuBr and t‐BuI, with monoalcohols (methanol, i‐propanol, and t‐butanol) have been studied at several temperatures during extended periods of time to acquire kinetic data for both the solvolytic step and the subsequent reactions. Reaction progress was followed by conductimetry, and calibration curves were obtained for all systems under study to derive concentration versus time curves for the significant intermediate species, the formed acid, HX. The GMS comprehensive mechanism, previously proposed by Gonçalves, Martins, and Simões for these reactions, was successfully tested using numerical integration associated with nonlinear regression, confirming the predicted distinct behaviors for methanol (and for that matter also for primary alcohols), secondary, and tertiary alcohols. Results show that accurate rate constants could be obtained in all cases and that the step that follows solvolysis can affect significantly the solvolytic rate constant and therefore any consequent reliable mechanistic analysis.     

One‐Pot synthesis of functional poly(methacrylate) by ATRP and 1,8‐Diazacyclo‐[5,4,0]undec‐7‐ene catalyzed transesterification

A facile one‐pot 1,8‐diazacyclo‐[5,4,0]undec‐7‐ene (DBU) catalyzed transesterification/atom transfer radical polymerization (ATRP) strategy has been successfully developed through the combination of copper/DBU‐catalyzed ATRP and DBU‐catalyzed transesterification reactions. Well‐defined poly(methacrylate)s with various side ester groups have been synthesized by ATRP and transesterification of acyl donor 2,2,2‐trifluoethyl methacrylate with various alcohols, such as benzyl alcohol, n‐butanol, iso‐propyl alcohol, methanol, triethylene glycol monomethyl ether, propargyl alcohol, and 6‐azido‐1‐hexanol by the one‐pot process. Kinetic studies indicate that the ATRP process proceeded in a controllable manner without the interference of the transesterification reactions. Expansion of the binary system to a higher level ternary system has been successfully achieved by the combination of copper(I)‐catalyzed azide–alkyne cycloaddition, transesterification, and ATRP reactions. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2998–3003     

Effect of Different Counterions of the Manganese Salt as Catalyst on the Kinetics of Resorcinol‐Based Belousov–Zhabotinsky Reaction

Kinetic studies on the Belousov–Zhabotinsky (BZ) system with various metal ions as catalysts have been carried out for a long time, but the effect of counteranions associated with the metal ion solution used as the catalyst in the BZ reaction has not been explored. Thus, we have chosen some metal salts as catalysts having the metal ion (Mnⁿ⁺) but with various anions to study the role of different anionic moieties of catalyst on the oscillatory behavior of the resorcinol‐based BZ reaction system. It is found that organic‐type anionic moieties marginalize the role of organic substrates in the reaction system. On the other hand, the inorganic counterions of the catalyst show salting out effects, thereby increasing the ionic strength, which affects the mobility (diffusion) of the ions in our system performed under batch conditions.     

Stabilization of self‐assembled microdroplets using short chain alcohols

The condensation of water vapor on a volatile polymeric solution leads to a porous surface after evaporation of both solvent and water. However, the stabilization of the water microdroplet is of great importance, which can be achieved using specific polymer or adding a third substance to the polymer solution. Short chain alcohols (methanol, ethanol, and n‐propanol) are utilized to fabricate a self‐assembled porous honeycomb film of linear, low molecular weight polystyrene using the breath figure technique. A combination of breath figure processing and the effect of alcohol on a water droplet can stabilize the pattern and make pores on the surface of the polymer film. The quality of the porous honeycomb film is strongly dependent on the type of alcohols and the concentration of polymer. In a specific range of polymer and alcohol concentration, pores cover all the surface of the polymer film. This method offers the possibility of producing a honeycomb structure with no trace of additive residual after the fabrication process and avoiding polymer modification. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 709–718