Here, the employment of subcritical water as an environmentally benign media has shown a certain potential for the hydrolysis ofiminodiaeetonitrile (IDAN). Additives (such as NH3.H2O, (NH4)2CO3, K2CO3) were sele...Here, the employment of subcritical water as an environmentally benign media has shown a certain potential for the hydrolysis ofiminodiaeetonitrile (IDAN). Additives (such as NH3.H2O, (NH4)2CO3, K2CO3) were selected to investigate the reactivity ofiminodiacetonitrile in the solutions of these species in the subcritical region for the possibility of preparing iminodiacetic acid (IDA) salts. A series of reactions were performed in a high temperature and pressure batch reactor with temperature ranging from 200 to 260 ℃, time ranging from 4 to 10 min, pressure ranging from 5 to 25 MPa and varying concentration of additives to consider the influence of these parameters on the yield of IDA salts. Reactivity of IDAN was not illustrated with the conversion but with respect to the yield of resultant IDA salts. The results demonstrate that hydrolysis reactivity of IDAN under the examined conditions has shown a remarkable sensitivity to the pH of the system at initial point of the reaction stage, and temperature effect is also obvious. Based on the results, possible reaction pathway and mechanism were proposed.展开更多
Developing high-efficiency and low-cost catalysts towards oxygen evolution reaction(OER)is extremely important for overall water splitting and rechargeable metal-air batteries.Herein we propose a promising organometal...Developing high-efficiency and low-cost catalysts towards oxygen evolution reaction(OER)is extremely important for overall water splitting and rechargeable metal-air batteries.Herein we propose a promising organometallic coordination polymer(OCP)induced strategy to construct hierarchical N-doped carbon framework with NiFe nanoparticles encapsulated inside(NxFe@N-C)as a highly active and stable OER catalyst.The synthesis of OCP precursor depends on the unique molecular structure of iminodiacetonitrile(IDAN),which can coordinate with metal ions to form Ni2Fe(CN)6 with prussian blue analogs(PBA)structure.Unlike previous PBA-induced methods,the thickness of the carbon layer covering the surface of the metal core can be well controlled during the pyrolysis through adjusting the amount of IDAN,which builds a wonderful bridge for investigating the relationship between carbon layer thickness and catalytic performance.Both the experimental characterizations and theoretical studies validate that a suitable carbon layers thickness leads to optimal OER activity and stability.By optimizing the structure and composition,the optimized Ni_(3)Fe@N-C with hierarchical framework exhibits the low overpotentials(260 mV at 10 mA cm^(-2);320 mV at 50 mA cm^(-2)),improved kinetics(79 mV dec^(-1)),and robust long-term stability,which exceeds those of benchmark RuO_(2).展开更多
文摘Here, the employment of subcritical water as an environmentally benign media has shown a certain potential for the hydrolysis ofiminodiaeetonitrile (IDAN). Additives (such as NH3.H2O, (NH4)2CO3, K2CO3) were selected to investigate the reactivity ofiminodiacetonitrile in the solutions of these species in the subcritical region for the possibility of preparing iminodiacetic acid (IDA) salts. A series of reactions were performed in a high temperature and pressure batch reactor with temperature ranging from 200 to 260 ℃, time ranging from 4 to 10 min, pressure ranging from 5 to 25 MPa and varying concentration of additives to consider the influence of these parameters on the yield of IDA salts. Reactivity of IDAN was not illustrated with the conversion but with respect to the yield of resultant IDA salts. The results demonstrate that hydrolysis reactivity of IDAN under the examined conditions has shown a remarkable sensitivity to the pH of the system at initial point of the reaction stage, and temperature effect is also obvious. Based on the results, possible reaction pathway and mechanism were proposed.
基金the financial supported by the National Natural Science Foundation of China(Nos.22109073,22072067 and 21875112)the Natural Science Foundation of Jiangsu Province(No.BK20200711)+2 种基金supported from the National and Local Joint Engineering Research Center of Biomedical Functional Materials and a project sponsored by the Priority Academic Program Development of Jiangsu Higher Education InstitutionsZ.Li thanks Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_1326)China Scholarship Council(No.202006860026).
文摘Developing high-efficiency and low-cost catalysts towards oxygen evolution reaction(OER)is extremely important for overall water splitting and rechargeable metal-air batteries.Herein we propose a promising organometallic coordination polymer(OCP)induced strategy to construct hierarchical N-doped carbon framework with NiFe nanoparticles encapsulated inside(NxFe@N-C)as a highly active and stable OER catalyst.The synthesis of OCP precursor depends on the unique molecular structure of iminodiacetonitrile(IDAN),which can coordinate with metal ions to form Ni2Fe(CN)6 with prussian blue analogs(PBA)structure.Unlike previous PBA-induced methods,the thickness of the carbon layer covering the surface of the metal core can be well controlled during the pyrolysis through adjusting the amount of IDAN,which builds a wonderful bridge for investigating the relationship between carbon layer thickness and catalytic performance.Both the experimental characterizations and theoretical studies validate that a suitable carbon layers thickness leads to optimal OER activity and stability.By optimizing the structure and composition,the optimized Ni_(3)Fe@N-C with hierarchical framework exhibits the low overpotentials(260 mV at 10 mA cm^(-2);320 mV at 50 mA cm^(-2)),improved kinetics(79 mV dec^(-1)),and robust long-term stability,which exceeds those of benchmark RuO_(2).