The effects of two catalyst fabrication techniques, impregnation method and colloidalmethod, on the performance of the oxygen electrode are studied and the difference in the catalyticactivity of the two kinds of catal...The effects of two catalyst fabrication techniques, impregnation method and colloidalmethod, on the performance of the oxygen electrode are studied and the difference in the catalyticactivity of the two kinds of catalysts towards oxygen reduction are also analyzed with the aid ofTEM and XRD. Based on the results and analysis, the following conclusions are obtained :thecatalyst fabricatin technique exerts an effect on the performance of the oxygen electrode, com-paring the performance of the Pt/C catalyst prepared by impregnation method with that of thePt/C catalyst prepared by colloidal method, the latter shows a higher catalytic activity towardsoxygen reduction; Pt/C electrocatalyst has small particle size and large fraction of Pt(111) crystalsurface.展开更多
The main difficulty in the extensive commercial use of polymer electrolyte membrane fuel cells （PEMFCs） is the use of noble metals such as Pt-based electrocatalyst at the cathode, which is essential to ease the oxyg...The main difficulty in the extensive commercial use of polymer electrolyte membrane fuel cells （PEMFCs） is the use of noble metals such as Pt-based electrocatalyst at the cathode, which is essential to ease the oxygen reduction reaction （ORR） in fuel cells （FCs）. To eliminate the high loading of Pt-based electrocatalysts to minimize the cost, extensive study has been carried out over the previous decades on the non-noble metal catalysts. Development in enhancing the ORR performance of FCs is mainly due to the doped carbon materials, Fe and Co-based electrocatalysts, these materials could be considered as probable substitutes for Pt-based catalysts. But the stability of these non-noble metal electrocatalysts is low and the durability of these metals remains unclear. The three basic reasons of instability are： （i） oxidative occurrence by H2O2, （ii） leakage of the metal site and （iii） protonation by probable anion adsorption of the active site. Whereas leakage of the metal site has been almost solved, more work is required to understand and avoid losses from oxidative attack and protonation. The ORR performance such as stability tests are usually run at low current densities and the lifetime is much shorter than desired need. Therefore, improvement in the ORR activity and stability afe the key issues of the non-noble metal electrocatalyst. Based on the consequences obtained in this area, numerous future research directions are projected and discussed in this paper. Hence, this review is focused on improvement of stability and durability of the non-noble metal electrocatalyst.展开更多
文摘The effects of two catalyst fabrication techniques, impregnation method and colloidalmethod, on the performance of the oxygen electrode are studied and the difference in the catalyticactivity of the two kinds of catalysts towards oxygen reduction are also analyzed with the aid ofTEM and XRD. Based on the results and analysis, the following conclusions are obtained :thecatalyst fabricatin technique exerts an effect on the performance of the oxygen electrode, com-paring the performance of the Pt/C catalyst prepared by impregnation method with that of thePt/C catalyst prepared by colloidal method, the latter shows a higher catalytic activity towardsoxygen reduction; Pt/C electrocatalyst has small particle size and large fraction of Pt(111) crystalsurface.
基金supported by the National Natural Science Foundation of China(21306119)the Key Research and Development Projects in Sichuan Province(2017GZ0397,2017CC0017)+1 种基金the Science and Technology Project of Chengdu(2015-HM01-00531-SF)the Outstanding Young Scientist Foundation of Sichuan University(2013SCU04A23)
文摘The main difficulty in the extensive commercial use of polymer electrolyte membrane fuel cells （PEMFCs） is the use of noble metals such as Pt-based electrocatalyst at the cathode, which is essential to ease the oxygen reduction reaction （ORR） in fuel cells （FCs）. To eliminate the high loading of Pt-based electrocatalysts to minimize the cost, extensive study has been carried out over the previous decades on the non-noble metal catalysts. Development in enhancing the ORR performance of FCs is mainly due to the doped carbon materials, Fe and Co-based electrocatalysts, these materials could be considered as probable substitutes for Pt-based catalysts. But the stability of these non-noble metal electrocatalysts is low and the durability of these metals remains unclear. The three basic reasons of instability are： （i） oxidative occurrence by H2O2, （ii） leakage of the metal site and （iii） protonation by probable anion adsorption of the active site. Whereas leakage of the metal site has been almost solved, more work is required to understand and avoid losses from oxidative attack and protonation. The ORR performance such as stability tests are usually run at low current densities and the lifetime is much shorter than desired need. Therefore, improvement in the ORR activity and stability afe the key issues of the non-noble metal electrocatalyst. Based on the consequences obtained in this area, numerous future research directions are projected and discussed in this paper. Hence, this review is focused on improvement of stability and durability of the non-noble metal electrocatalyst.
