The catalytic hydrogenation of D-glucose over a 3 wt% Ru/C catalyst was studied varying the operating conditions in mild conditions range to optimize the obtention of D-sorbitol. The stirring speed, temperature, press...The catalytic hydrogenation of D-glucose over a 3 wt% Ru/C catalyst was studied varying the operating conditions in mild conditions range to optimize the obtention of D-sorbitol. The stirring speed, temperature, pressure, and initial glucose concentration were varied between 250 - 700 rpm, 343 - 383 K, 0.5 - 2 MPa, and 0.033 - 0.133 M, respectively. To verify the absence of mass transport limitations, the diffusion of reagents in the gas-liquid interface, the liquid-solid interface, and the internal diffusion in the particles were evaluated. Under the operating conditions studied, the reaction rate showed an order with respect to H<sub>2</sub> of 0.586 and with respect to glucose of 0.406. The kinetic data were adjusted using 3 general models and 19 different sub-models based on Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetics. Model 3a was the best one interpreting the aqueous phase hydrogenation of glucose (both reagents competitively adsorbed on the catalyst). The H<sub>2</sub> adsorption is dissociative and the rate-limiting step is the surface chemical reaction.展开更多
It is reported for the first time that the Pt - Ru/C catalyst was prepared with the solid phase reaction method.Cyclic voltammetric measurements indicated that the anodic peak potential of ethanol at the electrode wit...It is reported for the first time that the Pt - Ru/C catalyst was prepared with the solid phase reaction method.Cyclic voltammetric measurements indicated that the anodic peak potential of ethanol at the electrode with the Pt - Ru/C catalyst prepared with the solid phase reaction method was0.54V and the peak current was100mA · cm -2 .While the anodic peak potential and peak current were0.64V and43mA · cm -2 respectively at the Pt - Ru/C catalyst prepared with the traditional liquid phase reaction method.It illustrated that the electrocatalytic activity of the Pt - Ru/C catalyst prepared with the solid phase reaction method was much better than that of the Pt - Ru/C catalyst prepared with the traditional liquid phase reaction method.It is because the Pt - Ru/C catalyst prepared with the solid phase reaction method is of low crystallinity and high dispersivity.展开更多
The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental a...The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental analysis, IR, XPS, electronic spectra and 31 P NMR. The results show that the complex of η 2 form can be formed by C 60 bonding to Ru(NO) 2(PPh 3) 2 in the σ π way and there is hyperconjugation effect in the molecule. So electrons will flow easier and photoelectric effect for this new compound is expected. In addition, the structure of the complex has been supposed. The ruthenium is 4 coordinate in the complex, bonding to two carbon atoms, to one PPh 3 and to one NO.展开更多
文摘The catalytic hydrogenation of D-glucose over a 3 wt% Ru/C catalyst was studied varying the operating conditions in mild conditions range to optimize the obtention of D-sorbitol. The stirring speed, temperature, pressure, and initial glucose concentration were varied between 250 - 700 rpm, 343 - 383 K, 0.5 - 2 MPa, and 0.033 - 0.133 M, respectively. To verify the absence of mass transport limitations, the diffusion of reagents in the gas-liquid interface, the liquid-solid interface, and the internal diffusion in the particles were evaluated. Under the operating conditions studied, the reaction rate showed an order with respect to H<sub>2</sub> of 0.586 and with respect to glucose of 0.406. The kinetic data were adjusted using 3 general models and 19 different sub-models based on Langmuir-Hinshelwood-Hougen-Watson (LHHW) kinetics. Model 3a was the best one interpreting the aqueous phase hydrogenation of glucose (both reagents competitively adsorbed on the catalyst). The H<sub>2</sub> adsorption is dissociative and the rate-limiting step is the surface chemical reaction.
基金supported by the National Natural Science Foundation of China (20673040, 20876062)National High-Tech Research and Development Program of China (863) (2009AA05Z119)~~
文摘It is reported for the first time that the Pt - Ru/C catalyst was prepared with the solid phase reaction method.Cyclic voltammetric measurements indicated that the anodic peak potential of ethanol at the electrode with the Pt - Ru/C catalyst prepared with the solid phase reaction method was0.54V and the peak current was100mA · cm -2 .While the anodic peak potential and peak current were0.64V and43mA · cm -2 respectively at the Pt - Ru/C catalyst prepared with the traditional liquid phase reaction method.It illustrated that the electrocatalytic activity of the Pt - Ru/C catalyst prepared with the solid phase reaction method was much better than that of the Pt - Ru/C catalyst prepared with the traditional liquid phase reaction method.It is because the Pt - Ru/C catalyst prepared with the solid phase reaction method is of low crystallinity and high dispersivity.
文摘The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental analysis, IR, XPS, electronic spectra and 31 P NMR. The results show that the complex of η 2 form can be formed by C 60 bonding to Ru(NO) 2(PPh 3) 2 in the σ π way and there is hyperconjugation effect in the molecule. So electrons will flow easier and photoelectric effect for this new compound is expected. In addition, the structure of the complex has been supposed. The ruthenium is 4 coordinate in the complex, bonding to two carbon atoms, to one PPh 3 and to one NO.
