Catalytic properties and activity of copper and silver containing Al-pillared bentonite for CO oxidation


TURGUT BAŞOĞLU F. , Balci S.

JOURNAL OF MOLECULAR STRUCTURE, vol.1106, pp.382-389, 2016 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 1106
  • Publication Date: 2016
  • Doi Number: 10.1016/j.molstruc.2015.10.072
  • Title of Journal : JOURNAL OF MOLECULAR STRUCTURE
  • Page Numbers: pp.382-389
  • Keywords: Pillared bentonite, SEM/EDS, XPS, FTIR, CO oxidation, Mechanism, WET PEROXIDE OXIDATION, PREFERENTIAL OXIDATION, CARBON-MONOXIDE, CLAY CATALYSTS, NO, CU, REDUCTION, PHENOL, CE, TEMPERATURE

Abstract

Al-pillared bentonite (Al-PB) using bentonite obtained from the Middle Anatolia region (Hancili) was synthesized, and Cu@Al-PB and Ag@Al-PB were obtained after the second metal impregnation step. Cu/AlPB prepared using a hydrothermal method was obtained with a Cu/(Cu + Al) mole ratio of 0.05. The SEM/EDS, scanning electron microscopy/energy dispersive X-ray spectroscopy analyses indicated that the impregnation method resulted in a higher copper loading in the structure. Based on the XPS, X-ray photoelectron spectroscopy analysis, the aluminum in all of the samples was in the Al2O3 form with 2s and 2p3 orbitals. Although no copper peaks were observed for Cu/Al-PB, the 2p3 and 2p1 orbitals of copper as well as the 3d3 and 3d5 orbitals of silver were observed in the copper or silver impregnated samples, respectively. Metal incorporation resulted in an increase especially in the strength of the Bronsted acid peaks in the FTIR, Fourier transform infrared spectra. The intensity of the peaks corresponding to the Bronsted sites did not change substantially as pyridine desorption temperature increased. The impregnated samples created a decrease in the 50% conversion temperature for carbon monoxide oxidation. Cu@Al-PB, which was calcined at 500 degrees C, gave a carbon monoxide conversion that was as high as 100% at approximately 200 degrees C and maintained its activity to 500 degrees C. In the impregnated samples, the reaction may use the surface oxygen provided by the metal oxide. (C) 2015 Elsevier B.V. All rights reserved.