The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum c...The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum catalysts(Pt/C/PTFE) with high efficiency as reported previously for LPCE were prepared and comprehensive performance evaluation method is applied to evaluate the separation behaviors of LPCE systematically. Experimental results indicate that the optimum reaction temperature of 60–80℃ and the molar feed ratio G/L of 1.5–2.5 would lead to higher separation efficiencies. As to the packing method, a random packing mode with a packing ratio of hydrophobic catalysts 0.25 is recommended. In addition, thermodynamic analysis corresponds well with experimental results under lower temperature and G/L, while the suppression of kinetic factors should not be neglected when T > 80℃ and G/L > 1.5.展开更多
The vacuum arc melting method was used to prepare ZrCo1-xCrx(x=0,0.025,0.05,0.075,0.1)alloys.Afterward,the crystal structure,hydrogenation kinetics,thermodynamic properties,and disproportionation performance of ZrCo1-...The vacuum arc melting method was used to prepare ZrCo1-xCrx(x=0,0.025,0.05,0.075,0.1)alloys.Afterward,the crystal structure,hydrogenation kinetics,thermodynamic properties,and disproportionation performance of ZrCo1-xCrx(x=0-0.1)alloys were investigated.The x-ray diffraction spectra demonstrated that ZrCo1-xCrx(x=0-0.1)alloys contained ZrCo and ZrCo2 phases,and their corresponding hydrides consisted of ZrCoH3 and ZrH phases.The activation behaviors of Cr-substituted samples were significantly promoted.The activation time of ZrCo was 7715 s while that of ZrCo0.9Cr0.1 was 195 s.The improvement of kinetics can be attributed to the catalytic hydrogenation of ZrCr2.The activation energy for the hydrogenation of ZrCo was 44.88-kJ·mol^-1 H2 and decreased to 40.34-kJ·mol^-1 H2 for ZrCo0.95Cr0.05.The plateau pressure and width of the pressure-composition-temperature curves decreased slightly as Cr content increased.The extent of disproportionation of ZrCo was 83.68%after being insulated at 798 K for 10 h and decreased slightly to 70.52%for ZrCo0.9Cr0.1.The improvement of anti-disproportionation performance can be attributed to increase in the activation energy of disproportionation from 167.46-kJ·mol^-1 H2 for ZrCo to 168.28-kJ·mol^-1 H2 for ZrCo0.95Cr0.05.展开更多
基金Supported by the National Key Research and Development Program of China(2017YFE0300302)the National Natural Science Foundation of China(21503199,21406212)Key Project of Applied&Basic Research of Sichuan Province(18YYJC1594)
文摘The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum catalysts(Pt/C/PTFE) with high efficiency as reported previously for LPCE were prepared and comprehensive performance evaluation method is applied to evaluate the separation behaviors of LPCE systematically. Experimental results indicate that the optimum reaction temperature of 60–80℃ and the molar feed ratio G/L of 1.5–2.5 would lead to higher separation efficiencies. As to the packing method, a random packing mode with a packing ratio of hydrophobic catalysts 0.25 is recommended. In addition, thermodynamic analysis corresponds well with experimental results under lower temperature and G/L, while the suppression of kinetic factors should not be neglected when T > 80℃ and G/L > 1.5.
基金the National Natural Science Foundation of China(Grant Nos.21573200,2017YFE0301505,21601165,21401173,21573200,and 51731002).
文摘The vacuum arc melting method was used to prepare ZrCo1-xCrx(x=0,0.025,0.05,0.075,0.1)alloys.Afterward,the crystal structure,hydrogenation kinetics,thermodynamic properties,and disproportionation performance of ZrCo1-xCrx(x=0-0.1)alloys were investigated.The x-ray diffraction spectra demonstrated that ZrCo1-xCrx(x=0-0.1)alloys contained ZrCo and ZrCo2 phases,and their corresponding hydrides consisted of ZrCoH3 and ZrH phases.The activation behaviors of Cr-substituted samples were significantly promoted.The activation time of ZrCo was 7715 s while that of ZrCo0.9Cr0.1 was 195 s.The improvement of kinetics can be attributed to the catalytic hydrogenation of ZrCr2.The activation energy for the hydrogenation of ZrCo was 44.88-kJ·mol^-1 H2 and decreased to 40.34-kJ·mol^-1 H2 for ZrCo0.95Cr0.05.The plateau pressure and width of the pressure-composition-temperature curves decreased slightly as Cr content increased.The extent of disproportionation of ZrCo was 83.68%after being insulated at 798 K for 10 h and decreased slightly to 70.52%for ZrCo0.9Cr0.1.The improvement of anti-disproportionation performance can be attributed to increase in the activation energy of disproportionation from 167.46-kJ·mol^-1 H2 for ZrCo to 168.28-kJ·mol^-1 H2 for ZrCo0.95Cr0.05.
