Activation of a sepiolite with dilute solutions of HNO3 and subsequent heat treatments: II. Determination of surface acid centres

作者：José Luis Solís Bonilla, J. de D. López-González, A. Ramīrez-Sāenz, F. Rodrı́guez-Reinoso, C. Valenzuela-Calahorro · 发表于：Clay Minerals · 年份：1981 · DOI：10.1180/claymin.1981.016.2.05 · 被引用次数：32 · 研究领域：Clay minerals and soil interactions、Iron oxide chemistry and applications、Adsorption and biosorption for pollutant removal

Abstract A sepiolite from Toledo, Spain, was activated with dilute solutions of HNO3 (0·25, 0·50 and 0·75 m) followed by heat treatment at 110, 200, 300, 400 and 500°C for 10 h. The retention of n-butylamine in cyclohexane solution was used to follow the variation of surface acid centres of the sepiolite as a function of the acid and heat treatments, these reaching a maximum for the product treated with 0·75 m HNO3 and heated at 300°C. Acid treatments within the range 0·50–0·75 m and subsequent heat treatment at 200–300°C for 10 h yielded products with the highest surface activity.