Catalyst characterization nitrogen physisorption

The catalysts and their precursors were characterized using various techniques, viz. TGA (TGA/SDTA 851 from Mettler TOLEDO), CO chemisorpiton, nitrogen physisorption (Quantachrome Autosorb-6B), Temperature Programmed Reduction (TPR, at 10 K/min in a flow of 7.6% H2 in Ar), elemental analysis (ICP-OES) and High Resolution Transmission ElectroMicroscopy (HRTEM), to optimise the procedures of preparation, calcination and pretreatment. 

The surface area of the catalysts was measured by conventional BET methods (nitrogen physisorption at -196°C using a Quanta Chrome-NOVA 1000 instrument). The actual metal loading was measured by inductively-coupled plasma / optical emission spectroscopy (ICP/OES). The acidity and basicity of the synthesized catalysts were measured by NHj and COj thermoprogrammed desorption, respectively, using an AMI-100 (Zeton-Altamira, Pittsburgh, PA) characterization system. The catalyst samples were reduced in 10% H /Ar at 450°C for 8 hours, followed by treatment in 10% NH,/He or 10% COj/He at 35°C and then by desorption up to 400°C with a heating rate of 10°C/min. 

The catalysts studied were characterized using X-ray powder diffraction (XRD), X-ray fluorescence analysis (XFA), transmission electron microscopy (TEM), X-ray adsorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and hquid nitrogen physisorption methods. 

The catalysts studied were characterized using XFA, TEM, XANES, EXAFS, XPS, and liquid nitrogen physisorption methods. The total organic caibon was detected by standard methodology of chemical oxygen demand (COD). 

The porous structure of the catalysts was characterized by mercury penetration and nitrogen physisorption, and die morphology of the surfiice die catalyst spheres was assessed by scanning dectron microscopy (SEM). The oxidation of carbon monoxide [10,11] was used to investigate the effects of transport limitations on the activity. The oxidation activity of the catalysts was correlated widi the textural data. 

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