@@@@Highlights •CeN was used as a catalyst to improve Mg(NH2)2–2LiH hydrogen storage performance.•The initial hydrogen absorption and desorption temperatures are reduced to 70 °C and 105 °C, respectively.•No cycling degradation occurred after 10 absorption/desorption cycles.•CeN enhances the hydrogen storage performance of the matrix by in-situ forming CeN/CeH2.51 composite interfaces.•The in-situ CeN/CeH2.51 composite interface formed accelerates the hydrogen exchange between the matrix and the outside.