Shouxin Bao^a, Junyan Li^a,b, Buyuan Guan^a, Mingjun Jia^{c, *}, Osamu Terasaki^b, and Jihong Yu^{a, d, *} Matter, Volume 3, Issue 2, 5 August 2020, Pages 498-508 https://doi.org/10.1016/j.matt.2020.06.021

^a. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
^b. School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P. R. China
^c. Key Laboratory of Surface and Interface Chemistry of Jilin Province, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
^d. International Center of Future Science, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China

Despite their open and uniform distributed active sites, the relatively low stability of coordination bonds in metal-organic frameworks (MOFs) limits their applications in catalytic reactions, especially under harsh environments. Herein, we report a design of MOF@mesoporous SiO₂ yolk-shell nanoreactors via a mesoporous silica coating followed by selective water etching strategy. Different from conventional alkali or acid etching method, water etching of MOF surface presents a green and cost-effective way to forming yolk-shell structure. The yolk-shell nanoreactors exhibit higher catalytic stability than bare MOF crystals in CO₂ cycloaddition with product yield remaining unchanged upon 3 cycles; this is owing to their permeable mesoporous SiO₂ shells, exposed active sites on MOF surfaces as well as protective shells. The design concept and synthetic strategy via selective water etching may be used to construct other highly stable MOF-based nanocatalysts, opening their applications in diverse catalytic reactions.