Synergetic catalysis of Ni@C@CeO2 for driving ab/desorption of MgH2 at moderate temperature

Multiple catalysts have exhibited high activity on improving the hydrogen storage performance of MgH 2 . Herein, the hydrogen ab/desorption kinetics of MgH 2 is significantly improved by using Ni@C@CeO 2 as the catalyst. The results show that 10 wt%-Ni@C@CeO 2 doped MgH 2 can absorb 4.51 wt% hydrogen within 60 min under low temperature 75 °C. Furthermore, the MgH 2 -Ni@C@CeO 2 composites release approximately 4.88 wt% H 2 within 10 min at 325 °C. Moreover, the composites show excellent cycling performance, with negligible decrease in hydrogen storage capacity, hydrogen uptake rate and hydrogen release rate after ten cycles at 350 °C. The Rietveld refinement of X-ray diffraction and transmittance electron microscopy measurements reveal that Mg 2 NiH 4 /Mg 2 Ni and CeH 2.73 phases are in-situ formed. The mutual conversion of “Mg 2 Ni/Mg 2 NiH 4 ” during hydrogen ab/desorption is a well-known “hydrogen pump” effect, which improvs the hydrogen storage performance of MgH 2 . The presence of CeH 2.73 accelerate the conversion of Mg 2 Ni/Mg 2 NiH 4 , which we call ‘facilitated hydrogen pump’ effect. This attempt paves a potential way to achieve high performance Mg-based composites hydrogen storage materials via collaborative action between Ni and Ce species.