Hollow silicalite-1 encapsulated nickel nanoparticles as highly stable catalysts in maleic anhydride hydrogenation

Abstract

Anchoring active metal particles in zeolite cages can significantly improve catalytic stability. In this study, hollow silicalite-1 (HoS-1) encapsulated Ni nanoparticles catalyst (Ni@HoS-1) was prepared using the impregnation method and applied in MA hydrogenation. The encapsulation mechanism was explained as the zeolite wall restricting the evaporation of water in HoS-1, hence Ni particles would be spontaneously enriched within the zeolite cage after drying and calcination. Experiments revealed the specially designed structure effectively protected Ni particles from leaching, and after 5 cycles in liquid-phase batch reactions, the final MA conversion of Ni@HoS-1 is 40.8 % higher than that of Ni/S-1 (85.5 % vs 44.7 %). Moreover, the low acidity of Ni@HoS-1 also delayed the accumulation of carbon deposits, extending the continuous reaction lifespan from 128 h of Ni/S-1 to 188 h. These findings provided a new perspective for the controllable locating of active metal sites against the supports.