Fe/SAPO-34催化剂制备及其CO加氢制低碳烯烃性能研究OA北大核心

Fischer-Tropsch synthesis is an important route to synthesize light olefins from syngas.However,precise control of the product selectivity and enhancing carbon utilization efficiency remains a challenge.Herein,a series of Fe/SAPO-34 catalysts with different Fe contents were prepared using negative pressure impregnation method,and their performance in CO hydrogenation reaction was evaluated.Combined N2 adsorption/desorption,XRD,SEM,NH3-TPD,and CO-TPD characterizations,the structure-performance relationship of the Fe/SAPO-34 catalysts was clarified.The results showed that with the increase of Fe loading,the strength and quantity of the acidity of the catalysts decreased sequentially,while the CO non-dissociation activation ability was weakened and the CO dissociation activation ability was enhanced,resulting in an increasing and decreasing trend in the selectivity of light olefins and oxygenates,respectively.Under a mild reaction conditions of t=200℃,p=2.0 MPa,GHSV=3300 h-1,in the carbon products containing CO2,the selectivity of light olefins and oxygenates over 5%Fe/SAPO-34 catalyst was 16.2%and 52.6%,respectively;while that over 25%Fe/SAPO-34 catalyst was 31.9%and 16.9%,respectively.A reasonable reaction mechanism was proposed based on the in situ IR characterization.This study provides a new way for the research and development of catalyst for light olefins synthesis with enhanced carbon utilization efficiency,showing promising application prospects.