采用两步法制备了过渡金属Fe、Co、Ni不同比例的介孔钼酸盐纳米棒。通过X-射线粉末衍射仪、扫描电子显微镜、透射电子显微镜、能谱仪以及氮气吸脱附测试系统等对其物相、形貌、结构、孔尺寸等性质进行了表征。结果表明,所合成出的不同Fe、Co、Ni比例的钼酸盐都呈现纳米棒状的形貌,并且在纳米棒上具有丰富的介孔,这些介孔可以提供更多的活性位点。通过调节催化剂中Fe、Co、Ni元素的比例,增强催化剂中多金属之间的协同作用,从而提高催化过程中的电荷转移速率,优化了析氧反应催化性质。催化性能测试结果显示,当Fe∶Co∶Ni=1∶1∶1时,样品具有最好的催化活性,电流密度为10 m A·cm^(-2)时的过电位仅为330 m V,该性能可以与商业用的贵金属催化剂Ir O2聘美。
The solvation of carbon dioxide in sea water plays an important role in the carbon circle and the world climate. The salting-out/salting-in mechanism of CO2 in electrolyte solutions still remains elusive at molecule l...
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The solvation of carbon dioxide in sea water plays an important role in the carbon circle and the world climate. The salting-out/salting-in mechanism of CO2 in electrolyte solutions still remains elusive at molecule level. The ability of ion salting-out/salting-in CO2 in electrolyte solution follows Hofmeister Series and the change of water mobility induced by salts can be predicted by the viscosity B-coefficients. In this work, the chemical potential of carbon dioxide and the dynamic properties of water in aqueous NaCl, KF and NaClO4 solutions are calculated and analyzed. According to the viscosity B-coefficients, NaClO4 (0.012) should salt out the carbon dioxide relative to in pure water, but the opposite effect is observed for it. Our simulation results suggest that the salting-in effect of NaClO4 is due to the strongly direct anion-CO2 interaction. The inconsistency between" Hofmeister Series and the viscosity B-coefficient suggests that it is not always right to indicate whether a salt belongs to salting-in or salting-out just from these properties of the salt solution in the absence of solute.
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