Enhanced permanganate oxidation of phenolic pollutants by alumina and potential industrial application

In this study, we found that alumina (Al2O3) may improve the degradation of phenolic pollutants by KMnO4 oxidation. In KMnO4/Al2O3 system, the removal efficiency of 2,4-Dibromophenol (2,4-DBP) was increased by 26.5%, and the apparent activation energy was decreased from 44.5 kJ/mol to 30.9 kJ/mol. The mechanism of Al2O3-catalytic was elucidated by electrochemical processes, X-ray photoelectron spectroscopy (XPS) characterization and theoretical analysis that the oxidation potential of MnO4- was improved from 0.46 V to 0.49 V. The improvement was attributed to the formation of coordination bonds between the O atoms in MnO4- and the empty P orbitals of the Al atoms in Al2O3 crystal leading to the even-more electron deficient state of MnO4-. The excellent reusability of Al2O3, the good performance on degradation of 2,4-DBP in real water, the satisfactory degradation of fixed-bed reactor, and the enhanced removal of 6 other phenolic pollutants demonstrated that the KMnO4/Al2O3 system has satisfactory potential industrial application value. This study offers evidence for the improvement of highly-efficient MnO4- oxidation systems.

Electrocatalytic performance of sonochemically synthesized Pt–Ni/C nanoparticles in fuel cell application

Developing high-performance electrocatalysts using simple and controllable methods is of interest to reduce the cost of polymer electrolyte membrane fuel cells. In this study, platinum is alloyed with nickel and supported on carbon (Pt–Ni/C) via an ultrasound-assisted route. The crystallite and particle sizes of the obtained nanoparticles were smaller than the commercial carbon-supported Pt nanoparticles. The sonochemically synthesized Pt–Ni/C nanoparticles exhibited superior electrocatalytic properties than the commercial Pt/C nanoparticles in the fuel cell operation. Electrochemical measurements performed with Pt–Ni/C electrocatalyst displayed excellent oxygen reduction and higher electrochemical active surface area (EASA). Optimum fuel cell performance based on peak power density using Pt–Ni/C electrocatalyst was observed as 0.28 W/cm2 at 0.39 V.