Ethane‐Bridged Periodic Mesoporous Organosilicas Functionalized with High Loadings of Carboxylic Acid Groups: Synthesis, Bifunctionalization, and Fabrication of Metal Nanoparticles

Abstract

Well-ordered periodic mesoporous organosilicas (PMOs) functionalized with high contents of carboxylic acid (COOH) groups, up to 85 mol % based on silica, were synthesized by co-condensation of 1,2-bis(triethoxysilyl)ethane (BTEE) and carboxyethylsilanetriol sodium salt (CES) under acidic conditions by using alkyl poly(oxyethylene) surfactant Brij 76 as a structure-directing agent. A variety of techniques including powder X-ray diffraction (XRD), nitrogen adsorption/desorption, Fourier-transformed infrared (FTIR), transmission electron microscopy (TEM), (13) C- and (29) Si solid-state nuclear magnetic resonance (NMR) were used to characterize the products. The materials thus obtained were used as an effective support to synthesize metal nanoparticles (Ag and Pt) within the channel of 2D hexagonal mesostructure of PMOs. The size and distribution of the nanoparticles were observed to be highly dependent on the interaction between the carboxylic acid functionalized group and the metal precursors. The size of Pt nanoparticles reduced from 3.6 to 2.5 nm and that of Ag nanoparticles reduced from 5.3 to 3.4 nm with the increase in the COOH loading from 10 to 50 %.

Ru Nanoparticles Embedded in Cubic Mesoporous Silica SBA-1 as Highly Efficient Catalysts for Hydrogen Generation from Ammonia Borane

“…Unfortunately, agglomeration of metal NPs still takes place because of the poor electrostatic interaction between the pure mesoporous silica and the metal NPs that decrease the performance of the catalyst. The surface of the mesoporous silicas is hence altered by integrating organic functional groups, such as carboxylic acid (-COOH) [43], amino (NH 2 ) [44], and thiol (SO 3 ) [45] etc., to confine the metal NPs firmly within the support.…”

Facile Fabrication of Well‐Dispersed Pt Nanoparticles in Mesoporous Silica with Large Open Spaces and Their Catalytic Applications

“…Here, the distinctive textural properties of the as‐prepared Pt@OMS such as enhanced surface area, pore volume, and enlarged pore size could improve the mass‐transport efficiency in the reactions. We suspected that the as‐prepared Pt@OMS nanocomposite could exhibit a unique catalytic performance, which is different from previous reports for which the metal particles or nanowires occupy most of the pore space of the supports . To prove this, we first used the gas‐phase oxidation of CO to CO 2 as a probe reaction to evaluate the catalytic activity of the Pt@OMS.…”

“…We suspected that the as-prepared Pt@OMSn anocomposite could exhibit au nique catalytic performance, which is different from previousr eports for which the metal particles or nanowires occupy most of the pore space of the supports. [23][24][25][26][27] To prove this, we first used the gas-phase oxidation of CO to CO 2 as ap robe reactiont oe valuatet he catalytic activity of the Pt@ OMS. For comparison, the Pt/OMS was also tested.…”

Gold Nanoparticles Confined in Vertically Aligned Silica Nanochannels and Their Electrocatalytic Activity Toward Ascorbic Acid

“…Various functional groups, such as amine,8 thiol,9 and carboxylic acid,10 can be anchored to the surface for subsequent metal NP deposition. To date, most of previous works have focused on the growth of NPs in mesoporous powder10c, 11 rather than mesoporous silica film (MSF) with regularly aligned mesochannels. The hybrid NP‐MSF structure would find attractive applications in surface catalysis and in the fabrication of nanodevices and optics 2a.…”