Preparation of PtNi/C electrocatalysts for direct methanol fuel cell via pulse microwave assisted polyol method

PtNi/C nanoparticles with different atomic ratios of Pt/Ni were produced in pulse microwave assisted polyol process. Transmission electron microscopy（TEM） images show uniform morphology. X-ray diffraction（XRD） pattern plus energy dispersive X-ray（EDX） spectroscopy suggests pure composition. Cyclic voltammogram study reveals that PtNi/C nanoparticles synthesized in pulse microwave assisted polyol process have better catalytic activity for the oxidation of methanol to carbon dioxide than those synthesized in continuous process.     

Preparation and electrochemical application of praseodymium modified TiO<Subscript>2</Subscript>-NTs/SnO<Subscript>2</Subscript>-Sb anode by cyclic voltammetry method

A Pr-doped TiO₂-NTs/SnO₂-Sb electrode was prepared by a simple method, cyclic voltammetry(CV). The methyl orange(MO)aqueous solution was selected as a simulated wastewater. The ordered microstructural TiO₂-NTs substrate was synthesized by an electrochemical method to obtain large specific surface area and high space utilization. The phase structure, electrode surface morphology and electrochemical properties of electrodes were characterized by XRD, SEM and electrochemical technology, respectively. The results showed that praseodymium oxide was successfully doped into the SnO₂-Sb film by CV method. Due to the doped Pr, the oxygen evolution potential increased from 2.25 V to 2.40 V. The degradation of MO was investigated by UV-vis. The C _t /C ₀ (φ) was studied as a function to obtain the optimal parameters, such as the amount of doped Pr, current density and initial dye concentration. In addition, the degradation process followed pseudo-first-order reaction kinetics and the rate constant was 0.099 3 min^-1. The result indicated that the introduction of Pr reduced the formation of oxygen vacancies or enhanced the formation of adsorbed hydroxyl radical groups on the surface, thus leading to better activity and stability.     

Experimental Investigation of Hydrodynamic Characteristic of a New Rotating Stream Tray

The hydrodynamic characteristic of a new rotating stream tray(NRST) was investigated. The tests were carried out using an air–water/oxygen experimental system in a column with a diameter of 500 mm. The hydrodynamic parameters studied were dry plate pressure drop, wet plate pressure drop, weeping, entrainment, and Murphree liquid efficiency. The results showed that the NRST has excellent performance in terms of high operational flexibility. The pressure drop, weeping rate, and entrainment rate remained low even under a high-capacity operation. Correlations of pressure drop, weeping, and entrainment for the NRST were obtained by regression analysis. The results can provide some important theoretical guidance for the development of this type of trays.