Urchin-like CoCu Bimetallic Nanocomposites for Catalytic Hydrogenolysis of Glycerol to Propanediols

Bimetallic CoCu nanocomposites were synthesized in polyol by using Ru as heterogeneous nucleation agent and stearic acid as surfactant, and their catalytic properties were investi- gated by hydrogenolysis of glycerol to propanediols. It was found that the surfactant could induce Co nanocrystals to form nanowires as structure-directing agent, while it＇s ineffective for Cu because only spherical Cu particles were produced under the same condition. When Co2＋ and Cu2＋ coexist in polyol, Cu2＋ is firstly reduced and forms the spherical particles, and then the Cu particles afford surface for the subsequential reduction of Co2＋ and growth of Co nanocrystals to form the nanorods, obtaining the urchin-like CoCu nanocomposites. The catalytic performance in selective hydrogenolysis of glycerol to propanediols proposed that the CoCu urchin-like nanocomposites was superior to the Co nanowires possibly due to that the synergistic effect between Co and Cu component promoted conversion of glyc- erol and obtained the higher propanediol yields based on the specific surface areas of the catalysts.

Thermodynamics of glycerol hydrogenolysis to propanediols over supported copper clusters: Insights from first-principles study

Copper catalysts supported on metal oxides display unique efficiency and selectivity in catalyzing glycerol hydrogenolysis to propanediols. Understanding the reaction at the molecular level is the key to rational design of better catalysts for propanediol synthesis, which is one of the major challenges for glycerol application in energy. In this work, extensive calculations based on periodic density functional theory were carried out to study thermodynamics of glycerol hydrogenolysis over binary model catalysts, including Cu/ZrO2 and Cu/MgO, with the focus to elucidate the competitive reaction pathways to produce the 1,2-propanediol (1,2-PDO) and 1,3-propanediol (1,3-PDO). Our results suggest that the reaction starts with glycerol dehydration on the metal oxide, followed by sequential hydrogenation over metal centers. Based on our explorations on the stabilities of adsorbed reactants, dehydrated intermediates and hydrogenated species along the reaction channels, the DFT calculations show that the 1,2-PDO formation will dominate in comparison to the 1,3-PDO from thermodynamic viewpoint. This is consistent with our experiments where the Cu catalysts seem to give the 1,2-PDO as a main product. The calculations and experiments also indicate that the Cu/MgO exhibits superior activities than Cu/ZrO2 for the hydrogenolysis of glycerol molecules.

固定化犁头霉菌在含有丙二醇的体系中转化RSA为皮质醇

固定化犁头霉菌在含有丙二醇的体系中转化ＲＳＡ为皮质醇王俊陈长治李保安张金红俞跃庭（南开大学分子生物学研究所天津３０００７１）皮质醇是重要的甾体激素类药物之一，目前国内采用淡紫色犁头霉菌（Ａｂｓｉｄｉａｏｒｃｈｉｄｉｓ）催化１１脱氧皮质醇醋酸酯（Ｒ...

Pt/Nb‐WO_x for the chemoselective hydrogenolysis of glycerol to 1,3‐propanediol: Nb dopant pacifying the over‐reduction of WO_x supports

Selective hydrogenolysis of glycerol to 1,3‐propanediol（1,3‐PD） is an important yet challenging method for the transformation of biomass into value‐added chemicals due to steric hindrance and unfavorable thermodynamics. In previous studies, chemoselective performances were found de‐manding and sensitive to H2 pressure. In this regard, we manipulate the chemical/physical charac‐teristics of the catalyst supports via doping Nb into WOx and prepared 1D needle‐, 2D flake‐, and 3D sphere‐stack mesoporous structured Nb‐WOx with increased surface acid sites. Moreover, Nb dop‐ing can successfully inhibit the over‐reduction of active W species during glycerol hydrogenolysis and substantially broaden the optimal H2 pressure from 1 to 5 MPa. When Nb doping is 2%, sup‐ported Pt catalysts showed promising performance for the selective hydrogenolysis of glycerol to 1,3‐PD over an unprecedentedly wide H2 pressure range, which will guarantee better catalyst sta‐bility in the long run, as well as expand their applications to other hydrogen‐related reactions.

Aquaglyceroporins but not orthodox aquaporins are involved in the cryotolerance of pig spermatozoa

Background:Aquaporins(AQPs)are a family of transmembrane water channels that includes orthodox AQPs,aquaglyceroporins(GLPs)and super AQPs.AQP3,AQP7,AQP9 and AQP11 have been identified in boar sperm,and they are crucial for sperm maturation and osmoregulation.Water exchange is an important event in cryopreservation,which is the most efficient method for long-term storage of sperm.However,the freezethaw process leads to sperm damage and a loss of fertilizing potential.Assuming that the quality of frozenthawed sperm partially depends on the regulation of osmolality variations during this process,AQPs might play a crucial role in boar semen freezability.In this context,the aim of this study was to unravel the functional relevance of the different groups of AQPs for boar sperm cryotolerance through three different inhibitors.Results:Inhibition of different groups of AQPs was found to have different effects on boar sperm cryotolerance.Whereas the use of 1,3-propanediol(PDO),an inhibitor of orthodox AQPs and GLPs,decreased total motility(P<0.05),it increased post-thaw sperm viability,lowered membrane lipid disorder and increased mitochondrial membrane potential(MMP)(P<0.05).When acetazolamide(AC)was used as an inhibitor of orthodox AQPs,the effects on post-thaw sperm quality were restricted to a mild increase in MMP in the presence of the intermediate concentration at 30 min post-thaw and an increase in superoxide levels(P<0.05).Finally,the addition of phloretin(PHL),a GLP inhibitor,had detrimental effects on post-thaw total and progressive sperm motilities,viability and lipid membrane disorder(P<0.05).Conclusions:The effects of the different inhibitors suggest that GLPs rather than orthodox AQPs are relevant for boar sperm freezability.Moreover,the positive effect of PDO on sperm quality suggests a cryoprotective role for this molecule.

A NEW POLYMER-BOUND 1,2-DIOL AS A PROTECTING AGENT FOR SYMMETRICAL DIALDEHYDE

A novel polymer-bound 1,2-diol, 3-polystyrylsulfonyl-1,2-propanediol (6) had been prepared by the reaction of sodium polystyrylsulfinate with allyl bromide, followed by oxidation and. hydrolysis or directly with 3-chloro-1,2-propanediol in the presence of a phase transfer catalyst, n-tetrabutylammonium iodide. The capacity of resin 6 for terephthaidehyde reached 1.43 mmol/g. The aldehydic groups attached to polymer 6 reacted with hydroxylamine hydrochloride or reduced by sodium borohydride giving p-formylbenzaldoxime (yield: 89%)and p-formyl-benzalcohol (yield: 734%), respectively. The high yields of these polymer-supported reactions showed that the polymer 6 possessed the effective isolation of its reactive sites.

Different Modes of the Effect of 1,2-Propanediol and Azone on Stratum Corneum Lipids

The stratum corneum (SC) controls the diffusion and penetration of drugs into and through the skin. In this investigation, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were used to study the effect of two enhancers, 1,2 propanediol and azone, on lipids extracted from SC (SC lipids). The two enhancers affected the SC lipids. However, their function modes were different. The penetration enhancing mechanisms of the two enhancers are discussed based on their effects on SC lipids and on their efficiencies in arbutin permeation enhancement.