Synthesis and characterization of Pd-MCM-type mesoporous nanocomposite materials

Şener, Canan
Noble metal incorporated MCM-41 based nanostructured mesoporous materials have attracted the attention of material researchers in recent years. Sorption characteristics of MCM materials can be improved by surface modification techniques. Besides surface modification, metal nanoparticles can also be produced within the pores of mesoporous materials. MCM-41 can act as host for several metal nanoparticles such as palladium. The present study is focused on the synthesis of Pd-MCM-41 nanocomposite catalytic materials by using different direct synthesis procedures, as well as an impregnation method. Impregnated samples were used to synthesize Pd nanoparticles inside the pores of MCM-41. In the direct hydrothermal synthesis of Pd-MCM-41, incorporation of the Pd metal was achieved by adding PdCl2, K2PdCl4 and Pd(NH3)4(NO2)3 solutions into the synthesis mixture. Syntheses were performed in acidic and basic routes. Hydrothermal synthesis was carried out in an autoclave at 120 oC. The solid product was filtered, washed, dried, calcined at 550 oC in a stream of dry air and reduced in a stream of hydrogen at 200 oC. In the case of impregnation, PdCl2 solution was added to a suspension of MCM-41. The product was evaporated to dryness, dried under vacuum and reduced with H2 gas at 200 oC. Physical and chemical properties and surface morphology of Pd-MCM-41 nanomaterials were characterized by using XRD, XPS, EDS, BET, SEM, TEM and TPR techniques. Very high Pd/Si ratios, as high as 0.45 and 0.18 were obtained in the mesoporous materials produced by the basic and acidic direct synthesis routes, respectively. The BET surface areas of these materials were found as 999 m2/g and 694 m2/g, respectively. These results showed that the basic direct synthesis procedure was highly successful for the incorporation of Pd into the mesoporous Si structure. In addition, EDS analysis of the Pd-MCM-41


Investigation of concentration profiles in carbon nanotube production reactor
Yalın, Mustafa; Özbelge, H. Önder; Department of Chemical Engineering (2009)
Carbon nanotubes have received considerable attention since their discovery due to their novel properties. They have potential application areas in physics, chemistry and biology. Arc discharge, laser furnace, chemical vapor deposition and floating catalyst methods are the most commonly used methods to produce carbon nanotubes. Although carbon nanotubes have superior properties compared to other materials, they could not be used widely. The main reasons of this are that continuous and large scale production...
Synthesis and Characterization of Aluminum Containing Silica Aerogel Catalysts for Degradation of PLA
Sivri, Seda; Dilek Hacıhabiboğlu, Çerağ; Sezgi, Naime Aslı (Walter de Gruyter GmbH, 2019-05-01)
Aluminum loaded silica aerogel based catalysts were synthesized by impregnation of aluminum into silica aerogel produced using sol-gel method in different aluminum loadings (2.5-15 wt%) to investigate their performances in degradation of polylactic acid (PLA).
Production of nano alumoxane from aluminum hydroxide
Sezgiker, Korhan; Gündüz, Güngör; Department of Chemical Engineering (2010)
Alumina (Al2O3) is one of the most widely used engineering ceramic. It can be used in a wide range of applications like electrical/thermal insulation, wear resistance, structural refractories, cutting tools, abrasives, catalyst carriers and coatings. A traditional ceramic process has several steps (i.e. powder synthesis and processing, shape forming, drying, organic burnout and densification). Accessing powders with sizes in the range of a couple of micrometers down to several tens of nanometers is consider...
Bioprocess development for therapeutical protein production
Çelik Akdur, Eda; Çalık, Pınar; Department of Chemical Engineering (2008)
In this study, it was aimed to develop a bioprocess using the Pichia pastoris expression system as an alternative to the mammalian system used in industry, for production of the therapeutically important glycoprotein, erythropoietin, and to form stoichiometric and kinetic models. Firstly, the human EPO gene, fused with a polyhistidine-tag and factor-Xa protease target site, in which cleavage produces the native termini of EPO, was integrated to AOX1 locus of P. pastoris. The Mut+ strain having the highest r...
Anodization of titanium alloys for orthopedic applications
Izmir, Merve; Ercan, Batur (Springer Science and Business Media LLC, 2019-03-01)
In recent years, nanostructured oxide films on titanium alloy surfaces have gained significant interest due to their electrical, catalytic and biological properties. In literature, there is variety of different approaches to fabricate nanostructured oxide films. Among these methods, anodization technique, which allows fine-tuning of oxide film thickness, feature size, topography and chemistry, is one of the most popular approaches to fabricate nanostructured oxide films on titanium alloys, and it has been w...
Citation Formats
C. Şener, “Synthesis and characterization of Pd-MCM-type mesoporous nanocomposite materials,” M.S. - Master of Science, Middle East Technical University, 2006.