In order to investigate the details of the process of pore condensation and hysteresis mechanisms in three-dimensional (3-D) pore networks, we performed a systematic study of the adsorption and pore condensation behavior of N2 (77.4 K) and Ar (77.4 and 87.3 K) in a 3-D ordered pore system, i.e., cubic Ia3̅d mesoporous KIT-6 silica materials with mode pore diameters ranging from ca. 5 nm up to 11 nm. KIT-6 silica is a porous material composed of two intertwined mesoporous subnetworks similar as in MCM-48, but this material can be prepared with much larger mean pore diameters. Accurate pore size analysis was performed by X-ray diffraction modeling and by state-of the art application of nonlocal density functional theory (NLDFT) on N2 (77.4 K) and Ar (87.3 K) sorption data. Furthermore, our data suggest that the width of the adsorption/desorption hysteresis loop observed for 3-D KIT-6 silica can be narrower as compared to that of pseudo-one-dimensional SBA-15 silica of the same pore size (i.e., in the pore diameter range from 6 to 8 nm). This specific behavior correlates well with the existence of the highly interconnected 3-D pore network of the KIT-6 material. Moreover, the results of our investigations are also consistent with previous observations that the SBA-15 pore system becomes more and more interconnected with increasing aging temperatures, i.e., SBA-15 changes from being a material with a pseudo-one-dimensional mesopore system to a material exhibiting a three-dimensional pore system resembling KIT-6 silica. These results provide new insights into the effects of pore interconnectivity on pore condensation and hysteresis behavior in both KIT-6 and SBA-15 silica materials and enable a more thorough understanding of the pore structure and textural properties of these materials.

Mesostructured metal oxides whose framework structures are engineered from materials other than silica make attractive research subjects. However, direct synthesis of these kinds of mesoporous materials using surfactants is quite difficult because, compared to silica, the surfactant/oxide composite precursors are often more susceptible to lack of condensation, redox reactions, or phase transitions accompanied by thermal breakdown of the structural integrity.[1] The nanocasting method for carbon, [2] pioneered by the group of Ryoo, [3] is an attractive alternative to the cooperative assembly routes, but using it to prepare non-carbon frameworks seems to be difficult. Previously, focus has mainly been on the creation of noble-metal replicas of small sections of the pore systems, which are then used to visualize their connectivity. [4] In this work we have explored the possibility of synthesizing frameworks of novel composition using silica-based templates. Spinel-type cobalt oxide (Co 3 O 4 ) was selected as a model because it is potentially useful for applications in catalysis, sensors, magnetic materials, and energy storage. For instance, Poizot et al. [5] proposed nanometer-sized transition-metal oxides as a new class of anode materials for lithium-ion batteries. Among them, cobalt oxides demonstrated the best electrochemical properties as lithium storage materials in lithiumion cells. Zhao's group has recently been successful in using microwave-digested (MWD) mesoporous silica (specifically, the two-dimensional hexagonal mesoporous silica, SBA-15, and the three-dimensional caged mesoporous silica, SBA-16) to synthesize nanowires and nanospheres of different metal oxides.[6] We show here that it is possible to create cubic Ia3dCo 3 O 4 using vinyl-functionalized, ordered, mesoporous silica [7] as a template, and demonstrate that the bulk antiferromagnet shows weak ferromagnetism at low temperatures. Following the synthesis procedure given in the Experimental section, a mesoscopically ordered array of Co 3 O 4 was obtained. Figure 1a shows the low-angle X-ray diffraction COMMUNICATIONS

The preparation and characterization of highly dispersed metal nanoparticles in mesoporous silica SBA-15 are reported. The functionalization with organosilane to generate a monolayer of charged groups on the pore surface facilitates uniform distribution of ionexchanged metal precursors in the channels of SBA-15, which, upon reduction, results in highly dispersed metal nanoparticles supported in SBA-15. Under mild reduction conditions, the surface functionality remains and so allows further metal incorporation cycles to achieve higher metal loading. After reduction in hydrogen flow, disk-shaped Pt nanoparticles in Pt/ SBA-15 and spherical Au nanoparticles in Au/SBA-15 have been characterized in the channels of SBA-15 by PXRD, XAS, and TEM. Secondary Pt incorporation in Au/SBA-15 produces coexisting small Pt nanoparticles with large Au nanoparticles in the host channels. This preparation method is capable of template synthesis of various metal nanostructures with controlled morphology and composition inside the channels of mesoporous materials.

A template synthetic method to prepare densely packed metal nanostructures in functionalized (MCM)‐41 and MCM‐48 is described. The intrachannel surface of host silica has been functionalized to carry positive charges for the accommodation of highly concentrated and negatively charged metal complexes. After reduction, Au and Pt nanowire bundles in MCM‐41 as well as Pd nanowire networks in MCM‐48 are formed. The Pt nanowire bundles in MCM‐41 are observed to grow along a preferred direction and stack along Pt {111} planes relative to the pore wall of the host. Furthermore, bimetallic AuPt alloy nanowire bundles in MCM‐41 have also been prepared and characterized.