Determination of Total Acid in Palygorskite Chemically Modified by N-Butylamine Thermodesorption

Abstract

The acid properties of palygorskite clay (R1) were studied using n-butylamine as probe molecule. A comparison was made of these properties in palygorskite clay (R1), in an acidified palygorskite (R2) and in acid palygorskite loaded with 2% of lanthanum (R3). The total acid properties were determined by FTIR (Fourier Transform Infrared) and TG-DTA (thermogravimetry). The acidity increased as follows: R3>R2>R1. The acid strength sites were classified as physisorbed, weak, medium and strong. The acid treatment did not change the site distribution, apparently only removing channel impurities. The introduction of lanthanum created many more acid sites and increased the specific area. Both weak and strong sites, which increased significantly, were considered new active acid sites produced by the lanthanum

Indigo dye waste recovery from blue denim textile effluent: a by-product synergy approach

“…Our data confirm the clay to be predominantly palygorskite, with traces of silica/quartz. Peaks obtained are typical for palygorskite with peaks at 2y = 8.3, 13.6, 19.7, and 26.61 corresponding to the primary diffraction of the (110), ( 200), (040), and (400) planes of the clay, respectively as reported by other authors 24,25 and confirmed by simulation with Cerius2 Molecular Modeling (Accelrys2).…”

Influence of aluminium incorporation in the preparation of zirconia-pillared clay and catalytic performance in the acetalization reaction

“…These results are very similar to those reported by Awate et al (2004) in their infrared study of pyridine adsorbed on Zr PILC. Ruiz et al (2002) reported also that n-butylamine thermodesorption give results similar to pyridine thermodesorption. The bands at 1445, 1590 and 1623 cm À1 are mainly assigned to a Lewis acid site.…”

Biodiesel obtained by ethylic transesterification using CuO, ZnO and CeO2 supported on bentonite

“…The use of n-butylamine as probe molecule for determination of acid properties is well known in literature [22,[28][29]. For instance, Ruiz et al [29] evaluated the acid sites of palygorskite clays by the mass loss of adsorbed n-butylamine, evaluated by thermogravimetric analysis.…”