Effect of La2O3 promoter on reaction performance of Fischer-Tropsch synthesis over Co/AC catalyst

The effect of La2O3 promoter on the reaction performance of Fischer-Tropsch synthesis over the activated carbon-supported cobalt-based (Co/AC) catalyst was investigated by means of CO hydrogenation, XRD, SEM, TPR and CO-TPD techniques. The results showed that the CO conversion increased from 27% to 56%, the selectivity for methane decreased from 16.5% to 7.8%, and the selectivity for C5+ increased from 55.4% to 74.7% with the addition of small amounts of La2O3 (w (La) = 0.7 % similar to 1.7%) to the Co/AC catalyst. However, high La loading (w (La) = 8.1 % -12.4%) led to the increase of methane selectivity. The results of XRD and SEM indicated that the existence of La2O3 could enhance the cobalt dispersion on the catalyst surface. The profiles of TPR and CO-TPD illuminated that there was a strong interaction between cobalt particles and La2O3 species, which led to the decrease of the reducibility of Co/AC catalyst, especially for the catalyst sample with high La loading, and the existence of La2O3 resulted in enhancement of CO adsorption at high temperature.