CAJ | 학술논문

以共沉淀法制备 FeAl 母体,采用浸渍法添加 Zn、K 和 Cu 助剂制成催化剂,利用低温 N2物理吸附、XRD、H2-TPR 等手段对 FeAl 母体和催化剂进行表征,并用固定床反应器考察它们的 CO2加氢反应性能。 XRD 结果表明,加入Al助剂、并采用无水乙醇洗涤沉淀能促进γ-Fe2 O3晶相生成,其中,Al2 O3/Fe2 O3质量比为10%的母体具有最强的γ-Fe2 O3衍射峰；加入Al使得母体中的 a-Fe2 O3晶粒粒径变小,引起比表面积明显增大；浸渍助剂过程没有改变上述两种效应。母体比表面积增大提高了助剂 Cu 的分散度,促进了催化剂还原,但γ-Fe2 O3晶相的生成才是催化剂的CO2加氢反应活性被提高的主要原因。
이공침정법제비 FeAl 모체,채용침지법첨가 Zn、K 화 Cu 조제제성최화제,이용저온 N2물리흡부、XRD、H2-TPR 등수단대 FeAl 모체화최화제진행표정,병용고정상반응기고찰타문적 CO2가경반응성능。 XRD 결과표명,가입Al조제、병채용무수을순세조침정능촉진γ-Fe2 O3정상생성,기중,Al2 O3/Fe2 O3질량비위10%적모체구유최강적γ-Fe2 O3연사봉；가입Al사득모체중적 a-Fe2 O3정립립경변소,인기비표면적명현증대；침지조제과정몰유개변상술량충효응。모체비표면적증대제고료조제 Cu 적분산도,촉진료최화제환원,단γ-Fe2 O3정상적생성재시최화제적CO2가경반응활성피제고적주요원인。
FeAl precursors ( remarked as P ) were prepared by co-precipitation method. Then they were impregnated with promoter Zn, K and Cu into ZnKCu/FeAl catalysts ( remarked as C ) . The precursors and catalysts were characterized by low temperature N2 adsorption, XRD and H2-TPR. CO2 hydrogenation over these catalysts was investigated in a fixed-bed reactor. With the addition of Al, the specific surface area of FeAl precursors and ZnKCu/FeAl catalysts was increased relative to that of Al-free samples. On the contrary, the crystallite size of a-Fe2 O3 was decreased by the added Al. The dispersed degree of Cu was raised in the catalysts containing Al. It is benefit for the reduction of ZnKCu/FeAl catalysts. However, the specific surface area and a-Fe2 O3 crystallite size of P-10 and C-10, in which the Al2 O3/Fe2 O3 mass ratio is 10 %, were similar to those of P-5 and C-5 with 5 % Al2 O3/ Fe2 O3 mass ratio, respectively. The phenomena were resulted from the strong g-Fe2 O3 phase in P-10 and C-10. It was evidenced that g-Fe2 O3 was formed only in the case of Fe and Al were co-precipitated, and the precipitate was washed by anhydrous ethanol in this study. The catalyst with strong g-Fe2 O3 phase was more active in CO2 hydrogenation than the catalysts with none or weak g-Fe2 O3 phase. This correlation was supported by the comparison between two catalysts with the same Al content, but different Fe2 O3 phases in them.