碱液电解制氢(Hydrogen Production By Alkaline Electrolysis,简称:ALK)分离模块是制氢制氧系统的环节之一,因为其中的设备和管道内的介质有氧气、氢气,按照相关标准需进行气压试验,而且客户也要求整体验收,因此整个撬块采取气压试验...碱液电解制氢(Hydrogen Production By Alkaline Electrolysis,简称:ALK)分离模块是制氢制氧系统的环节之一,因为其中的设备和管道内的介质有氧气、氢气,按照相关标准需进行气压试验,而且客户也要求整体验收,因此整个撬块采取气压试验最为适宜。又因为气压试验是非常危险的,通常情况下,气压储能大约是液压的2500倍。因此试压期间需要做好安全措施的同时,还需要考虑测压时间的缩短与风险的降低。我们在起初的试压中,发现耗时长,漏点检修慢,工人多且乱等诸多问题。现根据模块的自身结构以及介质流向的区域范围,利用阀门的切断功能,在不改变整体结构的情况下,提出将整体化变成区域分散化,整体试压变成区域分开试压的理论,由此一来,几个区域可以错峰工作,压力上升速度加快,气压空间变小,完美的实现了测压时间短,人工成本低,风险下降的愿望。通过试验论证,改进后的方案确达到我们的理论结果。展开更多
The development of a non-precious metal electrocatalyst （NPME） with a performance superior to commercial Pt/C for the oxygen reduction reaction （ORR） is important for the commercialization of fuel cells. We report...The development of a non-precious metal electrocatalyst （NPME） with a performance superior to commercial Pt/C for the oxygen reduction reaction （ORR） is important for the commercialization of fuel cells. We report the synthesis of a NPME by heat-treating Co-based metal organic frameworks （ZIF-67） with a small average size of 44 nm. The electrocatalyst pyrolyzed at 600 ~C showed the best performance and the performance was enhanced when it was supported on BP 2000. The resulting electrocatalyst was composed of 10 nm Co nanoparticles coated by 3-12 layers of N doped graphite layers which as a whole was embedded in a carbon matrix. The ORR performance of the electrocatalyst was tested by rotating disk electrode tests in O2-saturated 0.1 mol/L KOH under ambient conditions. The electrocatalyst （1.0 mg/cm~] showed an onset potential of 1.017 V （[vs. RHE] and a half-wave potential of 0.857 V （vs. RHE], which showed it was as good as the commer- cial Pt/C （20 BgPt/cm2）. Furthermore, the electrocatalyst possessed much better stability and re- sistance to methanol crossover than Pt/C.展开更多
The investigation of electrodeposition of rhenium in alkaline and acidic electrolytes was carried out, polarization curves were obtained by electrochemically and cyclically potentiodynamic methods. By the investigatio...The investigation of electrodeposition of rhenium in alkaline and acidic electrolytes was carried out, polarization curves were obtained by electrochemically and cyclically potentiodynamic methods. By the investigation of rhenium concentration, sulphuric acid, alkali, ammonium sulphate, temperature and acidity of solution, it was found that reaming velocity was an optimal regime and electrolyte composition for an obtaining of high quality rhenium deposits from an alkaline electrolyte and acidic electrolyte. It was defined that the process of electrodeposition of rhenium in alkaline electrolyte is accompanied by chemical polarization and the electrodeposition of rhenium in acidic electrolyte goes gradually with the formation of intermediate films of sediments,展开更多
The rational design and construction of inexpensive and highly active electrocatalysts for hydrogen evolution reaction(HER)is of great importance for water splitting.Herein,we develop a facile approach for preparation...The rational design and construction of inexpensive and highly active electrocatalysts for hydrogen evolution reaction(HER)is of great importance for water splitting.Herein,we develop a facile approach for preparation of porous carbon-confined Ru-doped Cu nanoparticles(denoted as Ru-Cu@C)by direct pyrolysis of the Ru-exchanged Cu-BTC metal–organic framework.When served as the electrocatalyst for HER,strikingly,the obtained Ru-Cu@C catalyst exhibits an ultralow overpotential(only 20 mV at 10 mA cm^(-2))with a small Tafel slope of 37 m V dec^(-1)in alkaline electrolyte.The excellent performance is comparable or even superior to that of commercial Pt/C catalyst.Density functional theory(DFT)calculations confirm that introducing Ru atoms into Cu nanocrystals can significantly alter the desorption of H_(2) to achieve a close-to-zero hydrogen adsorption energy and thereby boost the HER process.This strategy gives a fresh impetus to explore low-cost and high-performance catalysts for HER in alkaline media.展开更多
Photoelectrochemical （PEC） water splitting is a promising approach to harvest and store solar energy [1]. Silicon has been widely investigated for PEC photoelectrodes due to its suitable band gap （1.12 eV） matchin...Photoelectrochemical （PEC） water splitting is a promising approach to harvest and store solar energy [1]. Silicon has been widely investigated for PEC photoelectrodes due to its suitable band gap （1.12 eV） matching the solar spectrum [2]. Here we investigate employing nickel both as a catalyst and protecting layer of a p-type silicon photocathode for photoelectrochemical hydrogen evolution in basic electrolytes for the first time. The silicon photocathode was made by depositing 15 nm Ti on a p-type silicon wafer followed by 5 nm Ni. The photocathode afforded an onset potential of -0.3 V vs. the reversible hydrogen electrode （RHE） in alkaline solution （1 M KOH）. The stability of the Ni/Ti/p-Si photocathode showed a 100 mV decay over 12 h in KOH, but the stability was significantly improved when the photocathode was operated in potassium borate buffer solution （pH ≈ 9.5）. The electrode surface was found to remain intact after 12 h of continuous operation at a constant current density of 10 mA/cm^2 in potassium borate buffer, suggesting that Ni affords good protection of Si based photocathodes in borate buffers.展开更多
Developing highly efficient,cost-effective,and stable electrocatalysts for hydrogen evolution reaction(HER)is of considerable importance but remains challenging.Herein,we report the fabrication of a robust Ru-based el...Developing highly efficient,cost-effective,and stable electrocatalysts for hydrogen evolution reaction(HER)is of considerable importance but remains challenging.Herein,we report the fabrication of a robust Ru-based electrocatalyst,which comprises heterostructured Ru-Ru_(2)P nanoparticles that are embedded in the N,P-codoped carbon nanofibers(CNFs),through a synthetic strategy involving electrospinning and temperature-controlled pyrolysis treatment.The as-prepared Ru-Ru_(2)P catalyst(Ru-Ru_(2)P@CNFs)shows excellent HER catalytic activities with low overpotentials of 11 and 14 mV in acidic and alkaline media,respectively,to achieve a current density of 10 mA cm^(−2),which are superior to the individual components of pure Ru and Ru_(2)P catalysts.Density functional theory calculations demonstrate the existence of electronic coupling effect between Ru and Ru_(2)P at the heterointerfaces,leading to a well-modulated electronic structure with optimized hydrogen adsorption strength and enhanced electrical conductivity for efficient HER electrocatalysis.In addition,the overall synthetic strategy can be generalized for the synthesis of a series of transitional metal phosphide-based nanofibers,thereby holding a remarkable capacity for various potential applications.展开更多
文摘碱液电解制氢(Hydrogen Production By Alkaline Electrolysis,简称:ALK)分离模块是制氢制氧系统的环节之一,因为其中的设备和管道内的介质有氧气、氢气,按照相关标准需进行气压试验,而且客户也要求整体验收,因此整个撬块采取气压试验最为适宜。又因为气压试验是非常危险的,通常情况下,气压储能大约是液压的2500倍。因此试压期间需要做好安全措施的同时,还需要考虑测压时间的缩短与风险的降低。我们在起初的试压中,发现耗时长,漏点检修慢,工人多且乱等诸多问题。现根据模块的自身结构以及介质流向的区域范围,利用阀门的切断功能,在不改变整体结构的情况下,提出将整体化变成区域分散化,整体试压变成区域分开试压的理论,由此一来,几个区域可以错峰工作,压力上升速度加快,气压空间变小,完美的实现了测压时间短,人工成本低,风险下降的愿望。通过试验论证,改进后的方案确达到我们的理论结果。
基金supported by the National Basic Research Program of China(973 Program,2015CB932304)the National Natural Science Founda-tion of China(21436003)
文摘The development of a non-precious metal electrocatalyst （NPME） with a performance superior to commercial Pt/C for the oxygen reduction reaction （ORR） is important for the commercialization of fuel cells. We report the synthesis of a NPME by heat-treating Co-based metal organic frameworks （ZIF-67） with a small average size of 44 nm. The electrocatalyst pyrolyzed at 600 ~C showed the best performance and the performance was enhanced when it was supported on BP 2000. The resulting electrocatalyst was composed of 10 nm Co nanoparticles coated by 3-12 layers of N doped graphite layers which as a whole was embedded in a carbon matrix. The ORR performance of the electrocatalyst was tested by rotating disk electrode tests in O2-saturated 0.1 mol/L KOH under ambient conditions. The electrocatalyst （1.0 mg/cm~] showed an onset potential of 1.017 V （[vs. RHE] and a half-wave potential of 0.857 V （vs. RHE], which showed it was as good as the commer- cial Pt/C （20 BgPt/cm2）. Furthermore, the electrocatalyst possessed much better stability and re- sistance to methanol crossover than Pt/C.
文摘The investigation of electrodeposition of rhenium in alkaline and acidic electrolytes was carried out, polarization curves were obtained by electrochemically and cyclically potentiodynamic methods. By the investigation of rhenium concentration, sulphuric acid, alkali, ammonium sulphate, temperature and acidity of solution, it was found that reaming velocity was an optimal regime and electrolyte composition for an obtaining of high quality rhenium deposits from an alkaline electrolyte and acidic electrolyte. It was defined that the process of electrodeposition of rhenium in alkaline electrolyte is accompanied by chemical polarization and the electrodeposition of rhenium in acidic electrolyte goes gradually with the formation of intermediate films of sediments,
基金the National Key R&D Program of China(2018YFB0605700)the National Natural Science Foundation of China(51778570,51879230,21725101,21871244,21521001,and 21703145)+1 种基金China Postdoctoral Science Foundation(2019TQ0298,2019M660151)Fujian Institute of Innovation(CAS)。
文摘The rational design and construction of inexpensive and highly active electrocatalysts for hydrogen evolution reaction(HER)is of great importance for water splitting.Herein,we develop a facile approach for preparation of porous carbon-confined Ru-doped Cu nanoparticles(denoted as Ru-Cu@C)by direct pyrolysis of the Ru-exchanged Cu-BTC metal–organic framework.When served as the electrocatalyst for HER,strikingly,the obtained Ru-Cu@C catalyst exhibits an ultralow overpotential(only 20 mV at 10 mA cm^(-2))with a small Tafel slope of 37 m V dec^(-1)in alkaline electrolyte.The excellent performance is comparable or even superior to that of commercial Pt/C catalyst.Density functional theory(DFT)calculations confirm that introducing Ru atoms into Cu nanocrystals can significantly alter the desorption of H_(2) to achieve a close-to-zero hydrogen adsorption energy and thereby boost the HER process.This strategy gives a fresh impetus to explore low-cost and high-performance catalysts for HER in alkaline media.
文摘Photoelectrochemical （PEC） water splitting is a promising approach to harvest and store solar energy [1]. Silicon has been widely investigated for PEC photoelectrodes due to its suitable band gap （1.12 eV） matching the solar spectrum [2]. Here we investigate employing nickel both as a catalyst and protecting layer of a p-type silicon photocathode for photoelectrochemical hydrogen evolution in basic electrolytes for the first time. The silicon photocathode was made by depositing 15 nm Ti on a p-type silicon wafer followed by 5 nm Ni. The photocathode afforded an onset potential of -0.3 V vs. the reversible hydrogen electrode （RHE） in alkaline solution （1 M KOH）. The stability of the Ni/Ti/p-Si photocathode showed a 100 mV decay over 12 h in KOH, but the stability was significantly improved when the photocathode was operated in potassium borate buffer solution （pH ≈ 9.5）. The electrode surface was found to remain intact after 12 h of continuous operation at a constant current density of 10 mA/cm^2 in potassium borate buffer, suggesting that Ni affords good protection of Si based photocathodes in borate buffers.
基金financially supported by the Natural Science Foundation of Zhejiang Province (LQ20B030001 and LY20E020002)China Postdoctoral Science Foundation (2021M702305)。
文摘Developing highly efficient,cost-effective,and stable electrocatalysts for hydrogen evolution reaction(HER)is of considerable importance but remains challenging.Herein,we report the fabrication of a robust Ru-based electrocatalyst,which comprises heterostructured Ru-Ru_(2)P nanoparticles that are embedded in the N,P-codoped carbon nanofibers(CNFs),through a synthetic strategy involving electrospinning and temperature-controlled pyrolysis treatment.The as-prepared Ru-Ru_(2)P catalyst(Ru-Ru_(2)P@CNFs)shows excellent HER catalytic activities with low overpotentials of 11 and 14 mV in acidic and alkaline media,respectively,to achieve a current density of 10 mA cm^(−2),which are superior to the individual components of pure Ru and Ru_(2)P catalysts.Density functional theory calculations demonstrate the existence of electronic coupling effect between Ru and Ru_(2)P at the heterointerfaces,leading to a well-modulated electronic structure with optimized hydrogen adsorption strength and enhanced electrical conductivity for efficient HER electrocatalysis.In addition,the overall synthetic strategy can be generalized for the synthesis of a series of transitional metal phosphide-based nanofibers,thereby holding a remarkable capacity for various potential applications.
