Synergistic Catalytic Effects of Yb2O3@C, Gd2O3@C, and CeO2@C on Mg–La–Ni Alloys’ Hydrogen Storage Properties

来源：ACS Publications

Yb2O3@C, Gd2O3@C, and CeO2@C hybrid catalysts with porous, defect-rich structures were synthesized via a modified vaporization–carbonization method and incorporated (7 wt %) into Mg96La3Ni alloys by ball milling. Yb2O3@C increased hydrogen absorption, while Gd2O3@C and CeO2@C reduced it; all enhanced dehydrogenation, with CeO2@C most effective. At 360 °C, 3 wt % H2 was released in 3.1 min for pristine Mg96La3Ni, but only 1.0, 1.9, and 2.7 min with CeO2@C, Yb2O3@C, and Gd2O3@C, respectively. CeO2@C reduced the activation energy from 121.67 to 109.78 kJ/mol. This study highlights the novelty of combining rare-earth oxides with defective carbon supports, where in situ hydrides act as “hydrogen pumps” and carbon frameworks provide nucleation sites. This synergistic strategy enhances kinetics and cycling stability without altering thermodynamics, offering new insights for Mg-based hydrogen storage alloys.