Tuning catalytic performance in Fischer-Tropsch synthesis by metal-support interactions

Metal-support interactions in inverse catalysts prepared by adsorbing tetraethoxysilane (TEOS) on to Co₃O₄ can be manipulated by varying the solvent mixture, from which TEOS is taken up. Deposition of TEOS on Co₃O₄ nanoparticles in n-hexane results in the formation of silica oligomers after calcination at 573 K interacting strongly with cobalt(II,III)oxide. Modification of Co₃O₄ nanoparticles with TEOS in a hydrolysing environment results in a stronger interaction due to the formation of surface cobalt silicate formed through hydrolysis. The presence of surface silicates results in a strong increase in the turnover frequency of carbon monoxide consumption in the Fischer-Tropsch synthesis operating at close to industrial conditions. The obtained activity change is accompanied with a shift to a more paraffinic product.