To evaluate the H_(2)O_(2)‐tolerance of non‐Pt oxygen reduction reaction(ORR)catalysts as well as in‐vestigate the H_(2)O_(2)‐induced decay mechanism,the selection of an appropriate H_(2)O_(2) concentration is a p...To evaluate the H_(2)O_(2)‐tolerance of non‐Pt oxygen reduction reaction(ORR)catalysts as well as in‐vestigate the H_(2)O_(2)‐induced decay mechanism,the selection of an appropriate H_(2)O_(2) concentration is a prerequisite.However,the concentration criterion is still unclear because of the lack of in‐operando methods to determine the actual concentration of H_(2)O_(2) in fuel cell catalyst layers.In this work,an electrochemical probe method was successfully established to in‐operando monitor the H_(2)O_(2) in non‐Pt catalyst layers for the first time.The local concentration of H_(2)O_(2) was revealed to reach 17 mmol/L,which is one order of magnitude higher than that under aqueous electrodes test conditions.Powered by the new knowledge,a concentration criterion of at least 17 mmol/L is suggested.This work fills in the large gap between aqueous electrode tests and the real fuel cell working conditions,and highlights the importance of in‐operando monitoring methods.展开更多
In this paper, we use pre-column 2 times low-temperature cryo-trap enrichment--gas chromatography（GC） /nitrogen and phosphorus detector（NPD）to detect and analyze phosphine in Arctic pole area for the first time. T...In this paper, we use pre-column 2 times low-temperature cryo-trap enrichment--gas chromatography（GC） /nitrogen and phosphorus detector（NPD）to detect and analyze phosphine in Arctic pole area for the first time. The results show phosphine exists in all of the samples in Arctic pole biosphere and phosphine concentration in Arctic atmosphere is between 18.54- 132.18 ng/m^3, almost the same as that in Antarctic atmosphere; phosphine concentration in Dalian bay sea surface sediments is between 116. 8- 554.3 ng/kg, almost the same as that reported in Jiao-zhou bay. Our research of phosphine will shed new light on the mechanisms showing how the phosphorus supplement influences the biogeochemical cycle and global warming.展开更多
文摘巴基斯坦赫维利1 230 MW燃气联合循环电站为全球第一套投入商业运行的9HA燃机"二拖一"联合循环电站。以赫维利项目9HA联合循环发电机为例,深入研究了发电机漏氢监测系统,并对闭式循环冷却水系统漏氢监测进行了优化,创新设计了漏氢监测装置,有效监测氢冷发电机氢气泄漏,能够及时在分散控制系统(distributed control system,DCS)报警,进而停机检查并修复问题,提高了系统的安全性,保障了机组安全、高效运行。对国内外配置氢冷型发电机的燃气、燃煤发电机组漏氢监测设计均具有较高的借鉴和参考意义。
文摘To evaluate the H_(2)O_(2)‐tolerance of non‐Pt oxygen reduction reaction(ORR)catalysts as well as in‐vestigate the H_(2)O_(2)‐induced decay mechanism,the selection of an appropriate H_(2)O_(2) concentration is a prerequisite.However,the concentration criterion is still unclear because of the lack of in‐operando methods to determine the actual concentration of H_(2)O_(2) in fuel cell catalyst layers.In this work,an electrochemical probe method was successfully established to in‐operando monitor the H_(2)O_(2) in non‐Pt catalyst layers for the first time.The local concentration of H_(2)O_(2) was revealed to reach 17 mmol/L,which is one order of magnitude higher than that under aqueous electrodes test conditions.Powered by the new knowledge,a concentration criterion of at least 17 mmol/L is suggested.This work fills in the large gap between aqueous electrode tests and the real fuel cell working conditions,and highlights the importance of in‐operando monitoring methods.
基金Supported by the National High Technology Research and Development Programme of China ( No. 2008AA09Z114)the Polar Science Research Foundation ( No. 20070214)the Opening Foundation ( No. PCRRF08016) of State Key Laboratory of Pollution Control and Resource Reuse Nanjing University and the National Ocean science Foundation (No. 2008614)
文摘In this paper, we use pre-column 2 times low-temperature cryo-trap enrichment--gas chromatography（GC） /nitrogen and phosphorus detector（NPD）to detect and analyze phosphine in Arctic pole area for the first time. The results show phosphine exists in all of the samples in Arctic pole biosphere and phosphine concentration in Arctic atmosphere is between 18.54- 132.18 ng/m^3, almost the same as that in Antarctic atmosphere; phosphine concentration in Dalian bay sea surface sediments is between 116. 8- 554.3 ng/kg, almost the same as that reported in Jiao-zhou bay. Our research of phosphine will shed new light on the mechanisms showing how the phosphorus supplement influences the biogeochemical cycle and global warming.
