Core-shell particles with catalytic activity
AssigneeTotal Raffinage Chimie
InventorsVincenzo Roberto Calderone, Nirappurackal Raveendran Shiju, Gad Rothenberg, Daniel Curulla-Ferre
Life of this patent
Estimating the term…
Abstract
The present invention pertains to novel core-shell particles comprising a core of iron oxide and a shell of cobalt oxide, characterized in that they are spherical with a number average diameter, as measured by TEM, of between 1 and 20 nm. This invention is also directed to their uses in the manufacture of a catalyst, and to the method for preparing these particles, by precipitating cobalt oxide onto magnetite or hematite particles which are themselves precipitated from Fe(III) and optionally Fe(II) salts.
Claims7
Core-shell particles obtained according to a method comprising:
- (a) preparing an aqueous solution comprising a ferric salt, at a temperature of less than 50° C.;
- (b) adding at least one base to said aqueous solution, so as to obtain a suspension of iron oxide particles having a pH value of from 10 to 14;
- (c) washing the suspension;
- (d) adding a strong acid to the washed suspension to peptize the washed suspension;
- (e) reacting at least one base with said peptized suspension, until the pH reaches a value from 10 to 14, at a temperature of from 50 to 95° C.;
- (f) adding a cobalt salt to the heated suspension in order to obtain spherical particles having a core of iron oxide and a shell comprising cobalt oxide, wherein the spherical particles comprise a core of iron oxide and a shell of Co3O4, characterized in that the core-shell particles are spherical with a number average diameter, as measured by TEM, of between 1 and 20 nm.
Dependencies are inferred from the claim text.