燃料化学学报（中英文）2026，Vol.54Issue(5)：153-163,11.DOI:10.3724/2097-213X.2025.JFCT.0035
x-Fe5C2与θ-Fe3C在逆水煤气变换中的结构演变规律
Structural evolution regulation of x-Fe5C2 and θ-Fe3C in the reverse water-gas shift reaction
摘要
Abstract
Iron-based catalysts often undergo dynamic carburization and oxidation phase transitions in a CO2/H2 atmosphere.The identification of the active phase and the control of stability remain key challenges affecting their industrial application.This study employed a gas-solid carburization method to prepare high-purity single-phase x-Fe5C2(Hägg carbide)and θ-Fe3C(cementite),with their structural purity systematically confirmed by XRD and Mössbauer spectroscopy(MES).Using techniques including fixed-bed reactor tests(H2/CO2=1,0.1 MPa,270-420 ℃),pulse experiments(270 ℃)and in situ XRD(10％CO2/He,340 ℃),the catalytic performance and structural evolution pathways of these carbides in the reverse water-gas shift(RWGS)reaction were thoroughly investigated.The results indicate that x-Fe5C2 exhibits higher RWGS activity but is more susceptible to oxidation during the reaction.In contrast,θ-Fe3C demonstrates stronger anti-oxidation stability but lower RWGS activity.Under RWGS conditions with H2,θ-Fe3C can partially transform into x-Fe5C2.However,in 10％CO2 atmosphere,both carbides are directly oxidized to Fe3O4,with no observed phase transformation between the iron carbides.These findings reveal the differences in the evolution mechanisms of x-Fe5C2 and θ-Fe3C under different atmospheres,providing experimental basis for the regulation of phase structure and optimization of operational stability in iron-based Fischer-Tropsch and RWGS catalysts.关键词
x-Fe5C2/θ-Fe3C/RWGS反应/原位XRDKey words
x-Fe5C2/θ-Fe3C/RWGS reaction/in situ XRD分类
化学化工引用本文复制引用
孙泽平,梁瑞康,魏子都,张超,相宏伟,武建兵,刘兴武..x-Fe5C2与θ-Fe3C在逆水煤气变换中的结构演变规律[J].燃料化学学报（中英文）,2026,54(5):153-163,11.基金项目
Supported by the National Natural Science Foundation of China(22072079,22172183,22572210),Beijing Natural Science Foundation(L255001),Shanxi Province Basic Research Program(202403011241005).国家自然科学基金面上项目(22072079,22172183,22572210),北京市自然科学基金(L255001)和山西省基础研究计划(202403011241005)资助 （22072079,22172183,22572210）
