(582bt) How pH Affects the Metal Dispersion on Silica-HMS, MCM-41 and SBA-15 Supports

Dilip Kumar Mondal, Chandona Mondal, Shyamal Roy*

Department of Chemical Engineering, Jadavpur University, Kolkata-70032, West Bengal, India

Abstract: This work investigated the possibility of incorporation of platinum and palladium using impregnation method into several meso-structured silica supports (HMS, SBA-15, MCM-41) prepared by using sol-gel method followed by reduction process and to obtain supported Pt, Pd catalysts with highest Pt, Pd metal loading. Supports and catalysts were characterized by XRD, SEM, TEM analyzer and the metal dispersions at varied pH on silica mesoporous support were carried out by CO chemisorption technique and a range of metal dispersion from 64 to 94% was obtained and it was demonstrated that there exists pH optimum at about 11 for HMS, 12 for MCM-41 and 10 for SBA-15, which result in the highest metal dispersions, 95% for SBA-15, 94% for HMS and 82% for MCM-41. The pH of the impregnation solution influences the surface charge of the mesoporous support and therefore determines the strength of interaction between the metal precursor and the mesoporous support.

Keywords:HMS, SBA-15, MCM-41, pH, point zero charge, Pt-Pd catalyst

References

[1] D. T. On, S. Kaliaguine, Zeolite-Coated Mesostructured Cellular Silica Foams. J. Am. Chem. Soc. 125 (2003), 618-619.

[2] P. Schmidt-Winkel, et al. Mesocellular Siliceous Foams with Uniformly Sized Cells and Windows. J. Am. Chem. Soc. 121 (1999), 254-255.

[3] V. Degirmenci, A. Yilmaz, D. Uner, Selective Methane Bromination over Sulfated Zirconia in SBA15 catalysts. Catal. Today 142 (2009), 30-33.

Email Id:

Dr.Shyamal Roy; shyamal.roy@rutgers.edu

Dilip Kumar Mandol; dilip1004@gmail.com

Chandana Mondal; mondal.chandona@gmail.com