Nickel–Ceria Nanowires Embedded in Microporous Silica: Controllable Synthesis, Formation Mechanism, and Catalytic Applications

Designing highly efficient catalysts for use in fuel production is a highly attractive research area but still remains challenging. Herein, for the first time, ultrafine Ni nanoparticles (NPs) self-assembled on ceria nanowires (NWs) and then embedded in a microporous silica shell (denoted as Ni-CeO 2 @SiO 2 ) are successfully designed and synthesized via a one-pot facile strategy. The average diameter of Ni-CeO 2 NWs is just 2.9 nm, and the length is up to 102.7 nm. The resulting Ni-CeO 2 @SiO 2 exhibits high performance and 100% hydrogen selectivity for H 2 production from N 2 H 4 and N 2 H 4 BH 3 in aqueous solution. Unexpectedly, Ni-CeO 2 @SiO 2 also has good catalytic performance and thermal stability for CO 2 methanation. The high catalytic performance of Ni-CeO 2 @SiO 2 can be attributed to the synergistic electronic effect and strong interaction between Ni NPs and CeO 2 NWs with plenty of oxygen vacancies, as well as the unique structure effect. As an effective strategy, the present work provides an opportunity to embed ultrafine metal NPs-CeO 2 NWs into a microporous silica shell, which has broad application prospects in various catalytic fields.