Enhanced durability of Pd/CeO2-C via metal-support interaction for oxygen reduction reaction.

It is a challenge to improve the long-term durability of Pd-based electrocatalysts for oxygen reduction reaction (ORR) in fuel cells. Herein, Pd/CeO2-C-T (T= 800 °C, 900 °C and 1000 °C) hybrid catalysts with metal-support interaction are prepared from Ce-based metal organic framework precursor. Abundant tiny CeO2nanoclusters are produced to form nanorod structures with uniformly distributed carbon through a calcination process. Meanwhile, both carbon and CeO2nanoclusters have good contact with the following deposited surfactant-free Pd nanoclusters. Benefited from the large specific surface area, good conductivity and structure integrity, Pd/CeO2-C-900 exhibits the best electrocatalytic ORR performance: onset potential of 0.968 V and half-wave potential of 0.857 V, outperforming those obtained on Pd/C counterpart. In addition, the half-wave potential only shifts 7 mV after 6000 cycles of accelerated durability testing, demonstrating robust durability.

[Studies of interference source in laser Raman spectra of near infrared].

Many abnormal peaks in laser Raman spectra were found in determinations with laser illuminant of 785. 18 nm. After studies, it was found that the notch filter caused the interferences and the characteristics of the band pass filter were not good. The absorption spectral characteristics of notch filter were studied for the new and old of band pass filters.

[Studies of influences of environmental light on near-infrared laser raman spectra of sodium glutamic acid solution].

The near-infrared laser Raman spectra influenced by environmental light were studied in the determination of sodium glutamic acid solution. The environmental lights included natural light from outdoors and light from room fluorescent lamp. The results show that different influences on near infrared laser Raman spectra of sodium glutamic acid solution can be produced in different environmental light. There were some characteristic spectral lines, down peaks or sharpened peaks. These influences cannot be ignored. It is suggested that the determination of solution by near-infrared laser Raman spectra is carried out in dark-room or in dark cover to completely isolates the influences of the environment lights.