Bimetallic platinum–ruthenium nanoparticles immobilized on reduced graphene oxide-TiO2 (RGO-TiO2) support for ethanol electro oxidation in acidic media

The present work addresses the potentialities of Pt–Ru nanoparticles deposited on a graphene oxide (RGO) and TiO₂ composite support towards electrochemical oxidation of ethanol in acidic media relevant for fuel cell applications. To immobilize platinum–ruthenium bimetallic nanoparticles on to an RGO-TiO₂ nanohybrid support a simple solution-phase chemical reduction method is utilized. An examination using electron microscopy and energy dispersive X-ray spectroscopy (EDS) indicated that Pt–Ru particles of 4–8 nm in diameter are dispersed on RGO-TiO₂ composite support. The corresponding Pt–Ru/RGO-TiO₂ nanocomposite electrocatalyst was studied for the electrochemical oxidation of ethanol in acidic media. Compared to the commercial Pt–Ru/C and Pt/C catalysts, Pt–Ru/RGO-TiO₂ nanocomposite yields higher mass-specific activity of about 1.4 and 3.2 times, respectively towards ethanol oxidation reaction (EOR). The synergistic boosting provided by RGO-TiO₂ composite support and Pt–Ru ensemble together contributed to the observed higher EOR activity and stability to Pt–Ru/RGO-TiO₂ nanocomposite compared with other in-house synthesized Pt–Ru/RGO, Pt/RGO and commercial Pt–Ru/C and Pt/C electrocatalysts. Further optimization of RGO-TiO₂ composite support provides opportunity to deposit many other types of metallic nanoparticles onto it for fuel cell electrocatalysis applications.     

Electrosynthesis of eco-friendly electrocatalyst based nickel-copper bimetallic nanoparticles supported on poly-phenylenediamine with highest current density and early ethanol oxidation onset potential

Bimetallic catalysts have been investigated as the most efficient materials to accelerate the chemical transformations at the anode in Direct Ethanol Fuel Cells. A comparative study is presented here to synthesize Ni–Cu bimetallic nanoparticles for the ethanol oxidation reaction on three conducting polymers: poly-ortho-phenylenediamine, poly-meta-phenylenediamine, and poly-para-phenylenediamine. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Electrochemical Impedance Spectroscopy (EIS) were used to analyze the modified electrodes. A series of bimetallic Ni–Cu nanoparticles with tunable ratios were successfully synthesized by simply changing the concentrations of Nickel and Copper. It has been confirmed that the best Ni/Cu molar ratio was 25% in the aspect of catalytic performance. The electrocatalyst exhibited an excellent catalytic activity with an anodic current of 70.5 mA cm^?2 at the lowest onset potential of 0.39 V with impressive stability. Ni₄Cu₁/PpPD should be considered as a good alternative to noble metal anode catalyst.     

The alginate fermentation strain Pantoea sp. F16-PCAi-T3P21 and ethanol production

Bio-ethanol production from algae is a promising way to help solve the energy problem. Alginate is a major component of algae, but it cannot be utilized by existing ethanol fermentation microorganisms. In order to improve the utilization rate of brown algae, high alginate fermentation strains should be obtained. In this research, strains for algae fermentation were got from several experiments. The ethanol yield of strain A was the highest, which was 0.095 g/g (ethanol to alginate). The identification of strain A was carried out and it was 99% identical to Pantoea sp. F16-PCAi-T3P21. Fermentation experiments with different substrates were carried out, such as laminaran, mannitol, L. japonica and acid hydrolysate of L. japonica, and the ethanol yield rate of L. japonica acid hydrolysate was the highest, which reached 0.17 g/g ethanol to L. japonica. It showed that strain A can converse alginate to ethanol in a relatively high yield rate, and might be a promising strain with L. japonica as the substrate, we believe more research should be carried out on this strain.     

两种猴头菇复合物对胃粘膜损伤的辅助保护研究

目的研究2种猴头菇复合物对无水乙醇诱导的急性胃粘膜损伤模型辅助保护作用。方法将70只SD大鼠按体重随机分为空白对照组、模型对照组、阳性对照组、配方1(猴头菇提取物+壳聚糖+沙棘籽油)低、高剂量组,配方2(猴头菇提取物+壳聚糖)低、高剂量组, 10只/组,连续灌胃30 d。末次给药后,无水乙醇造模,游标卡尺测量出血点或出血带的长度和宽度,计算积分,并进行病理组织学观察评分。结果与空白对照组相比,模型对照组肉眼观察评分及组织病理学评分显著升高,有统计学差异(P0.01);与模型对照组相比,阳性对照组和配方1和配方2高剂量组组织病理学评分及肉眼观察评分降低(P0.05)。结论 2种猴头菇复合物对无水乙醇诱导的急性胃粘膜损伤模型具有辅助保护作用。     

Ethanol absorption from CO2 using solutions of glycerol and glycols

CO₂ stripping during fermentation is a possible way of increasing the production of ethanol in distilleries. Ethanol, water, and carbon dioxide are the main compounds in the exiting gas mixture. To date, few studies have proposed the use of absorption to recover ethanol from this mixture or have considered different absorbents for this purpose. This work evaluates different absorbent solutions used to recover ethanol vapor from CO₂ gas. Glycols and glycerol can provide easier separation of ethanol than water, with lower distillation energy demand. A statistical experimental design was used to compare the mass transfers of ethanol from the gas phase to the liquid phase, using solutions of glycerol, ethylene glycol, and diethylene glycol. High concentrations of these substances did not favor the absorption of ethanol. The best results were achieved with 25% absorbent solutions, which offered better options than water for the recovery of ethanol from CO₂ gas in absorption columns and could increase the productivity of first generation bioethanol production.     

Effect of cerium oxide prepared under different hydrothermal time on electrocatalytic performance of Pt-based anode catalysts

In this paper,CeO_2 with a pore size of 2-4 nm was synthesized by hydrothermal method.The CeO_2 modified graphene-supported Pt catalyst was prepared by the microwave-assisted ethylene glycol reduction chloroplatinic acid method,and the effect of the addition of CeO_2 prepared by different hydrothermal reaction time on the catalytic performance of Pt-based catalysts was investigated.The microstructures of CeO_2 and catalysts were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),specific surface area and pore size analyzer(BET),scanning electron microscopy(SEM) and electron spectroscopy(EDAX),transmission electron microscopy(TEM),and the catalysts electrochemical performance was tested by electrochemical workstation.The results show that the catalytic performance of the four catalysts with CeO_2 is better than that of the catalyst without CeO_2.Adding CeO_2 with a specific surface area of 120.15 m~2/g prepared by hydrothermal reaction time of 39 h to Pt/C synthesis catalyst,its electrocatalytic performance,stability and resistance to poisoning are the best.The electrochemical active surface area is 102.83 m~2/g,the peak current density of ethanol oxidation is 757.17 A/g and steady-state current density of 1100 s is 108.17 A/g which shows the lowest activation energy for ethanol oxidation reaction.When the cyclic voltammogram is scanned for 500 cycles,the oxidation peak current density retention rate is 87.74%.     

The control of paracetamol particle size and surface morphology through crystallisation in a spray dryer

The parameters governing the crystallisation of paracetamol using various conventional techniques has been extensively studied, however the factors influencing the drug crystallisation using spray drying is not as well understood. The aim of this work was to investigate the crystallisation of an active pharmaceutical ingredient through evaporative crystallisation using a spray dryer to study the physicochemical properties of the drug and to use semi-empirical equations to gain insight into the morphology and particle size of the dried powder. Paracetamol solutions were spray dried at various inlet temperatures ranging from 60 °C to 120 °C and also from a series of inlet feed solvent compositions ranging from 50/50% v/v ethanol/water to 100% ethanol and solid-state characterisation was done. The size and morphology of the dried materials were altered with a change in spray drying parameters, with an increase in inlet temperature leading to an increase in particle Sauter mean diameter (from 3.0 to 4.4 µm) and a decrease in the particle size with an increase in ethanol concentration in the feed (from 4.6 to 4.4 µm) as a result of changes in particle density and atomised droplet size. The morphology of the dried particles consisted of agglomerates of individual crystallites bound together into larger semi-spherical agglomerates with a higher tendency for particles having crystalline ridges to form at higher ethanol concentrations of the feed.     

改性氧化钛对羟乙基乙二胺水溶液解吸CO2的强化

羟乙基乙二胺（AEE）水溶液的CO₂循环吸收量高（1.2molCO₂/molAEE），吸收速度快，稳定性好，但解吸速度慢、解吸量少（0.8mol CO₂/mol AEE）是限制该技术广泛应用的主要原因。本文通过向AEE水溶液中添加质量分数为0.05%～0.20%的改性氧化钛（TiO₂-MWCNT和TiO₂-OH）强化AEE的解吸能力。CO₂循环吸收（40℃）-解吸（120℃）实验结果表明改性氧化钛的添加比氧化钛强化CO₂解吸效果更好，强化顺序为TiO₂-MWCNT＞TiO₂-OH；其对应的最大解吸速率分别为0.093L/min（质量分数0.15%）和0.083L/min（质量分数0.20%），相对于AEE水溶液，分别提高了32.9%和18.6%；其对应的最大解吸量分别为0.92molCO₂/molAEE（质量分数0.15%）和0.88molCO₂/molAEE（质量分数0.20%），分别提高了12.2%和9.7%；其对应的CO₂循环吸收量分别是0.95molCO₂/molAEE（质量分数0.15%）和0.89molCO₂/molAEE（质量分数0.15%），分别提高了18.75%和11.25%；5次循环吸收解吸实验结果表明改性氧化钛强化CO₂解吸效果稳定，具有较强的化学稳定性。对反应后的改性氧化钛进行XRD、BET、FTIR和SEM表征，结果表明改性氧化钛具有较强的结构稳定性。TiO₂-MWCNT和TiO₂-OH在促进有机胺溶液解吸CO₂方面具有一定的工业应用潜力。     

Comprehensive analysis on anomalous phenomenon of ethanol-soluble poly(vinyl butyral) membrane for ethanol recovery via pervaporation

Poly(vinyl butyral) (PVB) is selected as a promising ethanol-permselective membrane based on the solubility parameter theory; however, it exhibits anomalous water perm-selectivity in practical pervaporation (PV) process. Comprehensive analysis based on experimental and theoretical methods were carried out to explore the inherent mechanism of the anomalous performance. Firstly, sum frequency generation vibrational spectra and contact angle were developed to quantify the surface reconstruction of membrane in air and ethanol, which indicated that hydrophilic hydroxyl tended to expose on membrane surface with ethanol thus improving the membrane affinity to water. Meanwhile, swelling behaviors proved more water would accumulate in the ethanol swollen membrane. Furthermore, theoretical analysis in terms of sorption and diffusion process, based on the UNIFAC-FV model and Fujita free-volume theory, confirmed the mechanism of anomalous phenomenon of PVB membrane. The comprehensive investigation was expected to provide insights into the basic separation mechanism of PV process.