The Preparation of High-Surface-Area Pt/SiO2 Catalysts with Well-Defined Pore-Size Distributions

1995 ◽  
Vol 152 (2) ◽  
pp. 291-305 ◽  
Author(s):  
W.Q. Zou ◽  
R.D. Gonzalez
2013 ◽  
Vol 667 ◽  
pp. 425-434 ◽  
Author(s):  
Mohd Hanapiah Abdullah ◽  
Ismail Lyly Nyl ◽  
Mohamed Zahidi Musa ◽  
Mohamad Rusop Mahmood

Effect of PEG on the TiO2 electrode morphology for scattering enhanced properties of the modified paste containing TiO2 sol-gel mixed with Degussa P-25 were investigated. The high surface area of the scattering centres in this study were formed by using nano size particles ascribed from TiO2 sol-gel while the sub-micron size particles were utilized from the reaction of PEG on the Degussa P-25 particles. The pore size distributions were tailored by varying the PEG content in the fabricated electrodes. Higher surface area with adequate pore size of P30 electrode has contributed to higher JSC and efficiency (η) of 11.35450 mA/cm2 and 2.479624 %, respectively. Photocurrent action spectra of IPCE of the DSSC exhibit the maximum of 42 % at 550 nm correspond to the P30 TiO2 electrode. Overall results suggest that the incorporation of TiO2 sol-gel component mixed with TiO2 paste derived from commercially available nanopowder could enhance surface area as well as serves for better light scattering effect, while PEG addition creates adequate pore size distribution to maximize the dye adsorbed on the TiO2 electrode.


2020 ◽  
Vol 4 (3) ◽  
pp. 851-861 ◽  
Author(s):  
Nai-hsuan Hu ◽  
Chamika U. Lenora ◽  
Timothy A. May ◽  
Nathan C. Hershberger ◽  
Joseph C. Furgal

Specific pore size distributions of synthesized methylsilsesquioxane-based network materials stem from a combination of the solvation of monomers and growing oligomers, as well as miscibility of water in tested solvents; enabling specific analyte uptake materials.


2005 ◽  
Vol 11 (5) ◽  
pp. 1658-1664 ◽  
Author(s):  
Wen-Cui Li ◽  
An-Hui Lu ◽  
Wolfgang Schmidt ◽  
Ferdi Schüth

2014 ◽  
Vol 49 (1) ◽  
pp. 1-8
Author(s):  
US Akhtar ◽  
MK Hossain ◽  
MS Miran ◽  
MYA Mollah

Porous silica materials were synthesized from tetraethyl orthosilicate (TEOS) using Pluronic P123 (non-ionic triblock copolymer, EO20PO70O20) as template under acidic conditions which was then used to prepare polyaniline (PAni) and porous silica composites (PAnisilica) at a fixed molar ratio. These materials were characterized by nitrogen adsorption-desorption isotherm measured by Barrett-Joyner- Halenda (BJH) method and pore size distribution from desorption branch and surface area measured by the Brunauer-Emmett-Teller (BET) method, scanning electron microscopy (SEM), transmission electron microscopy (TEM), TEM-energy dispersive X-ray (EDX) and Fourier transform infrared (FT-IR) spectroscopy. The composite maintains its structure even after the polymerization and the polymer is dispersed on the inorganic matrix. The rod-like porous silica was about 1?m to 1.5 ?m long and on an average the diameter was in the range of 300- 500 nm. The SEM and TEM images show well ordered 2d hexagonal pore, high specific surface area (850 m2g-1) and uniform pore size of ca. 6.5 nm in diameter. After incorporation of PAni inside the silica pore, framework of porous silica did not collapse and the surface area of the composite was as high as 434 m2g-1 which was 5.5 time higher than our previous report of 78.3 m2g-1. Due to shrinkage of the framework during the incorporation of aniline inside the silica, the pore diameter slightly increase to 7.5 nm but still showing Type IV isotherm and typical hysteresis loop H1 implying a uniform cylindrical pore geometry. DOI: http://dx.doi.org/10.3329/bjsir.v49i1.18847 Bangladesh J. Sci. Ind. Res. 49(1), 1-8, 2014


1987 ◽  
Vol 4 (1-2) ◽  
pp. 87-104 ◽  
Author(s):  
Bruce D Adkins ◽  
Jill B. Heink ◽  
Burtron H. Davis

Scanning electron microscopic data, X-ray diffraction patterns and porosity measurements are consistent with a structure for an Mo-A12O3 catalyst series containing a single surface layer of Mo up to the point where the Mo loadings exceed the amount required for a monolayer. For greater Mo loadings than required for a monolayer, three dimensional orthorhombic MoO3 is also present. The cumulative pore volume, on an alumina basis, does not appear to be significantly altered by MoO3 loadings up to about 15 wt.%. The BET surface area, on an alumina basis, remains constant with Mo loading. However, the apparent surface area calculated from mercury penetration data decreases with Mo loading. For these materials with cylindrical pores, the Broekhoff-deBoer model for the calculation of pore size distributions produced closer agreement to the mercury penetration pore size distribution. This is in contrast to materials composed of nonporous spheres where the Broekhoff-deBoer model provided poorer agreement to mercury penetration results than either the Cohan or a packed sphere model. The results show that, within a factor of two the pore size distributions calculated from nitrogen adsorption and mercury penetration data are comparable.


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