Abstract

Significance Iron nitride holds great potential for further enhancing the performance of Fischer-Tropsch （FT） synthesis reactions due to its rich phase structure， unique carbonaceous characteristics， and favorable physicochemical adsorption properties.This paper reviews the research progress of iron nitride in FT synthesis. It facilitates the design and development of FT catalysts，contributing to the achievement of ‘carbon peaking’ and ‘carbon neutrality’.

Progress Common types of iron nitride include Fe₂N， Fe₃N， and Fe₄N. The main preparation methods of iron nitride are iron oxide reduction nitriding， iron salt nitriding， and nitriding of metal-organic framework materials. The phase transformation of iron nitride is related to μN and temperature. As a catalyst for FTh synthesis， iron nitride primarily produces high-carbon hydrocarbons， low-carbon olefins， and high-carbon alcohols. The selectivity for low-carbon olefins in iron nitride catalysts can be improved by adding carriers and additives. Under FTh reaction conditions， the nitrogen atoms in iron nitride can exchange with carbon atoms， forming iron carbide. Studies have shown that iron carbide remains the active phase in FTh synthesis. Despite these advancements， achieving high activity in iron nitride catalysts and high selectivity of target products remains an important challenge that needs to be addressed.

Conclusions and Prospects This paper systematically reviews the preparation of iron nitride and summarizes the current research on iron nitride catalysts for CO hydrogenation to produce high-carbon alcohols， low-carbon olefins， and high-carbon hydrocarbons. However， most existing studies on iron nitride focus on catalytic performance， and there has been no systematic research on the active phase structure of iron nitride catalysts， the phase transformationprocess of iron nitride during FTh reactions， or the relationship between iron nitride， iron carbide， and their chemical environment. Additionally， due to the similarity in crystal structure parameters between iron nitride and iron carbide， and the dynamic evolution of the active phase structure under high-temperature and high-pressure reaction conditions， there is an urgent need to employ in-situ characterization techniques to reveal the phase evolution of iron nitride under reaction conditions and identify the active phase.

Keywords：iron nitride； controlled preparation； phase structure； Fischer−Tropsch synthesis