Preparation of CuO@Mesoporous SiO2 Via Calcining Nanocasted Metal Organic Frameworks (MOFs) for Styrene Oxidation Reaction

Nanocasting SiO2 into metal organic frameworks (MOF) provides adequate protection for the pyrolysis of MOF into CuO nanoparticles and prevents their aggregation. The prepared CuO@SiO2 exhibited outstanding catalytic performance and excellent recyclability in the styrene oxidation reaction owing to the abundant active sites and the good stability brought by the SiO2 skeleton. A mesoporous silica bearing uniformly distributed copper oxide nanoparticles (CuO@mesoporous SiO2) was prepared through silica nanocasting copper metal organic frameworks (MOFs) followed by calcination. The nanocasting filled the micropores of MOFs with silica and then, the calcination removed the organic linker in MOFs and converted copper metal ions into CuO particles, resulting in the CuO@mesoporous SiO2 architecture. The characterization results indicated that the final product basically maintained the original MOF morphology and the mesoporous silica effectively prevented the aggregation of nanoparticles. In addition, the CuO@mesoporous SiO2 exhibited a superior activity for catalyzing the oxidation of styrene, which could be attributed to the fact that the dispersed CuO particles in mesoporous silica provided more accessible catalytic sites and better stability. This work provides a new strategy to prepare nanoparticles@mesoporous silica with adjustable morphology structure, which has a promising potential in the field of heterogeneous catalysis.