Recent progress has put the spotlight on functional nanoparticles encapsulated inside hollow silica nanospheres as socalled catalytic nanoreactors for various reactions. However, the synthetic methods used so far vary from one nanoparticle system to another, not providing access to the synthesis of a large variety of such materials. Here, we report an alternative, namely, a coordination-enhanced synthesis leading to a single system, which can directly produce a vast number of different hollow mesoporous silica nanoreactors with metal or metal-oxide nanoparticles inside their cavities (M@HMSNs or M x O y @HMSNs, where M stands for the chosen metal). We have successfully used the method with more than 21 different metals (Ru,

An atomically dispersed Waugh type [CoMoO] cluster is obtained, employing the most flexible structure unit Anderson type [Co(OH)MoO] as a precursor. The structure of the [CoMoO] cluster is identified by single crystal X-ray diffraction and also well characterized by FT-IR, ESI-MS, UV-Vis, EA, and TGA spectroscopy. Its 3D framework forms a quasi 2D material and possesses curved edge triangle shape nanopores with a diameter of 8.9 Å. The Co and Mo oxidation states and the related valence band and electronic state of Co are definitely confirmed by X-ray photoelectron spectroscopy (XPS), ultraviolet photoemission spectroscopy (UPS), and bond valence sum (BVS). The [CoMoO] cluster is a typical n-type inorganic semiconductor with a HOMO-LOMO gap of ca. 1.67 eV and exhibits reversible two-electron redox properties, evidenced by UPS, cyclic voltammetric (CV), and Mott-Schottky plot analyses. Furthermore, [CoMoO] can effectively generate O under laser (365 and 532 nm) and sunlight irradiation, detected using a water-soluble DAB probe. Such an n-type multielectron reservoir semiconductor anionic [CoMoO] cluster with thermal and electrochemical stability as an effective photosensitizer serves as a promising material in solar energy scavenging.

Hollow mesoporous nanoreactors with encaged functional nanoparticles are promising heterogeneous catalysts due to the advantages related to their hollow cavities. In this study, we employ metal ion-bound polymer micelles to synthesize PtSn alloy nanoparticle-encaged hollow mesoporous nanoreactors (PtSn@HMSNs), which contain ∼4 nm PtSn alloy NPs located in ∼13 nm hollow cavities and relatively large (∼9 nm) mesoporous channels in silica shells. Relative to monometallic Pt@HMSNs and supported Pt 1 Sn 0.3 /SiO 2 , Pt 1 Sn 0.3 @HMSNs exhibit greatly enhanced activity and selectivity for hydrogenation of furfural to furfuryl alcohol. At 1.0 MPa H 2 , 100 °C, and a furfural/Pt molar ratio of 1884:1, 97.5% of furfuryl alcohol yield was achieved in 5.0 h. The dramatically promoted catalytic performance of Pt 1 Sn 0.3 @HMSNs can be assigned to the confinement effect that the location of active NPs inside hollow cavities increases the collision rates between reactants and active NPs to promote catalytic activity, as well as the synergistic effect between Pt and Sn.

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PtRh bimetallic nanoparticle (NP)-encaged hollow mesoporous silica nanoreactors (PtRh@HMSNs) are prepared by employing metal-ion-containing charge-driven polymer micelles as templates. These nanoreactors feature ∼1−2 nm PtRh NPs in ∼11 nm hollow cavities of HMSNs. Among various Pt x Rh y @HMSNs, Pt 0.77 Rh 1 @HMSNs show the best catalytic performance for toluene hydrogenation. Under 30 °C, atmospheric H 2 pressure, and a toluene/(Pt+Rh) molar ratio of 200/1, Pt 0.77 Rh 1 @HMSNs reach 100.0% of methyl cyclohexane yield and demonstrate a much better catalytic performance than monometallic Pt@ HMSNs and Rh@HMSNs and their physical mixtures. Moreover, Pt 0.77 Rh 1 @HMSNs exhibit a good catalytic stability during recycling experiments. The enhanced performance of Pt 0.77 Rh 1 @HMSNs is ascribed to the interaction between Pt and Rh, the beneficial effect of the relatively large mesoporous channels for mass transfer, as well as the confinement effect of functional NPs inside hollow cavities.