Roger Jean Lussier

A novel clay-based catalytic material—preparation and properties

Abstract A novel acid-leached calcined kaolin has been prepared by careful control of the calcination and acid leach conditions. A narrow calcination window gives an extremely acid-reactive calcined kaolin, which develops high surface areas at a rate much faster than that of samples calcined outside this range. This more acid active calcined kaolin also allows the use of extremely low levels of acid, which results in most of the alumina being in the solid phase during the entire leach step. Al 27 NMR results indicate the most acid-reactive calcined clay has the lowest level of octahedral and the highest level of five-coordinate Al. Acids containing anions that do not complex with aluminum such as hydrochloric, nitric, or aluminum chloride work in this process, while acids containing anions that complex with aluminum such a sulfuric or phosphoric do not lead to the same high surface area, catalytically active products. Properly calcined and leached materials show a broad distribution of pores centered at about 40 A.

An estimate of surface acidity in amorphous catalysts from temperature-programmed desorption measurements. a simple tool for catalyst characterization

Abstract Temperature-programmed desorption is shown to be a simple, catalyst characterization tool that affords a qualitative and quantitative index of the total strong acidity and strong acid site strength of amorphous, solid acid catalysts and provides a measure of the surface acidity related to a standard catalyst micro-activity test.