Method for the preparation of a hydrocarbon synthesis catalyst material and the use thereof in a hydrocarbon synthesis process

A method for the preparation of a hydrocarbon synthesis catalyst material including the steps of:

• (i) providing Fe(II) carboxylate in solution;
• (ii) if the molar ratio of carboxyl and carboxylate groups, which groups have either reacted with iron or are free to do so, to Fe(II) in the solution of step (i) is not at least 3:1, adding a source of a carboxyl or a carboxylate group to the solution to ensure that said molar ratio is at least 3:1 prior to the completion of the oxidation of the Fe(II) carboxylate referred to in step (iii) below;
• (iii) treating the Fe(II) carboxylate in solution with an oxidising agent to convert it to Fe(III) carboxylate in solution under conditions which ensure that such oxidation does not take place simultaneously with any dissolution of Fe(0);
• (iv) hydrolysing the Fe(III) carboxylate solution resulting from step (iii) and precipitating one or more Fe(III) hydrolysis products;
• (v) recovering the one or more hydrolysis products of step (iv);
• and
• (vi) adding one or more promoters, or sources of promoter, during or subsequent to any of the preceding steps in order to produce a catalyst material in the form of a hydrocarbon synthesis catalyst precursor.