Research on the effect of ball milling time on the gaseous hydrogen storage properties of La0.7Pr0.3MgNi3.6Co0.4 alloy
In this paper,four kinds of La0.7Pr0.3MgNi3.6Co0.4 alloys were prepared by mechanical ball milling with ball milling times of 0.50,1,1.50 and 2 h.The structure and the gaseous hydrogen storage properties of the alloy have been systematically studied.The microstructure and phase structure of the alloy were characterized by scanning electron microscopy(SEM)and X-ray diffractometer(XRD).The gaseous hydrogen storage performance of the alloy was tested by PCT gaseous hydrogen storage tester.With the extension of milling time,the size of alloy powder decreases and the amount of amorphous structure increases gradually.Ball milling can shorten the activation incubation period and reduce the activation energy of hydrogen absorption from 61.83 kJ/mol to 38.08 kJ/mol.The en-thalpy change Δhof hydrogen absorption reaction decreases from 46.23 kJ/mol to 32.33 kJ/mol,and the entropy change Δsof hydro-gen absorption reaction decreases from 127.45 J/mol·K to 88.44 J/mol·K.
NETL
NSTL
万方数据
