文献类型：期刊文献

英文题名：Elucidating the synergistic fabrication of dual embedded (χ-Fe5C2 + θ-Fe3C) carbide nanocomposites in Na-FeCa@AC/HZSM-5 integrated catalyst for syngas conversion to aromatics

作者：Nawaz, Muhammad Asif[1]; Saif, Maria[1]; Li, Minzhe[1]; Song, Guiyao[1]; Zihao, Wang[1]; Chen, Chonghao[1]; Liu, Dianhua[1]

机构：[1] State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China

年份：2022

卷号：324

外文期刊名：Fuel

收录：EI(收录号：20222212184687)

语种：英文

外文关键词：Activated carbon - Aromatic compounds - Aromatization - Carbides - Catalyst activity - Catalyst selectivity - Fischer-Tropsch synthesis - Magnetite - Nanoparticles - Precipitation (chemical) - Sintering - Sols - Surface reactions - Synthesis gas

摘要：Herein, an activated carbon (AC) modified Fe-oxide catalyst has been employed in Na-FeCa@AC/HZSM-5 integrated catalytic system for the direct conversion of syngas to aromatics (STA). In comparison to the conventionally impregnated Fe/C catalysts, the spatial confinement of highly dispersed Fe3O4 nanocrystals in a rigid geometry of defective graphite sheet by the efficient modulation of different (AC, Ca) promoters, calcination environment and the surface carbon reactions in sol-precipitation method, potentially deflected the sintering and agglomeration behavior of Fe nanoparticles. The meliorated higher extent of CO chemisorption on the tuned Fe surface and the different reduction/carburization schemes cultivated the high-purity (54% χ-Fe5C2 + 44% θ-Fe3C) carbide nanoparticles. The encapsulation of perforated carbon patches during carburization favored the stabilization of highly active carbide phase under reaction conditions, where the subsequent precipitation of carbon elements led to the further recruitment of multi-layer carbide films for the accelerated CO dissociation and the partial decomposition of olefinic intermediates. Since, the dually embedded terrace carbide islands were rather enriched from one phase to another (27.3%θ-Fe3C 70.7%χ-Fe5C2) during the reaction, giving a simultaneously enhanced catalytic activity of 97% CO conversion and 60% aromatics selectivity while suppressing the net CO2 release (21%). The current study anticipates a promising scheme to formulize a highly active and stable iron-based catalyst to be integrated with HZSM-5 for STA process. ? 2022 Elsevier Ltd