Construction of Synergistic Fe5C2/Co Heterostructured Nanoparticles as an Enhanced Low Temperature Fischer–Tropsch Synthesis Catalyst

Iron and cobalt catalysts are two major categories for commercial Fischer–Tropsch synthesis (FTS) catalysts. The two types of catalysts have distinct merits and shortcomings while they are largely supplementary to each other. However, until now, there has been a lack of an efficient way to properly combine those two catalysts into a synergistic one which possesses the benefits of both catalysts. Herein, the Fe5C2/Co heterostructured nanoparticles (NPs) were constructed by a secondary growth strategy, where the Fe/Co molar ratio can be tuned from 3.3 to 25. Based on the FTS reaction evaluation, we observed that only with 0.6 wt % Co (Fe/Co = 12) incorporated, the Fe5C2/Co catalyst exhibits an activity four times higher than that of pure Fe5C2 catalyst at low temperature. In this catalyst, Co was responsible for the CO dissociation while Fe5C2 was responsible for the chain growth at 220 °C. The synergistic effect of both sites may lead to enhanced performance in FTS reaction. This result provides a perspective for the construction of Fe–Co bimetallic FTS catalysts.