Surface Properties of Metal-Incorporated Al-Pillared Interlayered Clay Catalysts Analyzed by Chemisorption and Infrared Analysis

Abstract

Al-pillared interlayered clay (Al-PILC) was synthesized using bentonite from the Hançılı region of Central Anatolia in Turkey. Samples of Al-PILC were impregnated with Cu or Ag to produce Cu@Al-PILC and Ag@Al-PILC. Cu/Al-mixed PILCs were also obtained using mixed metal sources having (Cu/(Cu+Al)) atom percents as 5 and 10. The FTIR intensities of Lewis acidity peaks decreased whereas the intensity of BrÖnsted acidity remained nearly the same for pyridine sorbed PILCs after desorption at 150°C compared to those of pyridine sorbed PILCs at room temperature. These results confirmed the presence of both types of acidities within the matrix. Metal incorporation increased total (weak+strong) ammonia adsorption. Metal incorporation increased the total acidities of Al-PILC from 281.1 μmol g-1 to 803-883 μmol g-1 by NH3 sorption at 50°C. The Cu/Al-mixed PILC(AP5) sample resulted 290 μmol g-1 number of active sites at an NH3 sorption temperature of 200˚C, with the corresponding strong active sites as 44.6 μmol g-1. Key Words: Pillared interlayered clay, Surface area, FTIR analysis, Ammonia sorption.