Effect of the Synthesis Method on Co-catalysts Based on MCM-41 for the Fischer–Tropsch Reaction

Abstract

In this work, cobalt catalysts based on ordered mesoporous materials of the MCM-41 type were synthesized and characterized. The synthesis of the catalysts was performed by using different methods: impregnation; incorporation of the metal in the synthesis gel and ionic exchange of the metal by the template. Different characterization techniques were used (N 2 adsorption-desorption, XRD, TPR, SEM and XPS) to study the textural and structural properties of the samples and the metal-support interaction corresponding to each method of synthesis. These samples were tested in the CO Hydrogenation (Fischer-Tropsch Synthesis) by measuring the CO conversion and the selectivity to CO 2 and some groups of hydrocarbons chains. The results show that structural and textural properties as well as the metal-support interactions are affected by the synthesis method. According to this study, catalytic performance is related to the properties of the samples, observing that the metal support interaction highly affects the activity and selectivity of the catalysts.

Incorporation of Co in Different Stages of the Synthesis of Al-PILC and Its Effect as a Fischer–Tropsch Catalyst

“…The three Co-PILC materials also show the Co 2p signal with the spin–orbital splitting 2p 1/2 and 2p 3/2 . The binding energy of the 2p 3/2 peak at ∼780 eV observed for samples Co­(susp) and Co­(cal) corresponds to the binding energy reported for Co 3 O 4 , as well as the spin–orbital splitting (15.1 eV) . The Co 2p spectrum of the Co­(dry) sample shows a broadband with a peak shifted to higher binding energies, which can be assigned to Co 3 O 4 and also the presence of cobalt in CoO or Co­(OH) 2 .…”

Fischer-Tropsch synthesis over Co/g-Al₂O₃ catalyst loaded on ceramic monolith-structured substrate

“…Ngày nay, nhiều nghiên cứu đã được thực hiện nhằm nâng cao hiệu quả kinh tế và tính cạnh tranh của các sản phẩm lỏng từ quá trình tổng hợp Fischer-Tropsch với các sản phẩm tương tự có nguồn gốc khoáng. Ví dụ, các kim loại quý như ruthenium (Ru) [5,6], rhenium (Re) [7,8], palladium (Pd) [9,10] và platinium (Pt) [11][12][13] đã được thêm vào hệ xúc tác điển hình của quá trình tổng hợp Fischer-Tropsch như Cobalt (Co) [14][15][16] và sắt (Fe) [17][18][19][20] với mục đích giảm độ chọn lọc các sản phẩm phụ, đồng thời tăng hiệu suất thu sản phẩm lỏng thông qua sự cải thiện khả năng hydro hóa CO. Bên cạnh sử dụng chất xúc tiến, các chất mang khác nhau như -Al2O3 [8,21,22], SBA-15 [23][24][25] và MCM-41 [26,27] cũng đã được khảo sát. Andrei và cộng sự đã chứng minh rằng, xúc tác cobalt trên chất mang silica có đường kính lỗ xốp lớn hơn 3 nm cho hiệu quả thu sản phẩm lỏng vượt trội so với các xúc tác cùng loại trên chất mang có đường kính lỗ xốp nhỏ hơn [28].…”

Effect of Process-Condition-Dependent Chain Growth Probability and Methane Formation on Modeling of the Fischer–Tropsch Process

“…In the FT process, syngas (CO + H 2 ) is converted to versatile final products, which are diverse mixtures of various hydrocarbons with carbon chains corresponding to gases (typically range from C 1 to C 4 ), liquids (from C 5 to C 20 ), and waxes (C 21+ ), depending upon the process conditions, such as the temperature, pressure, H 2 /CO feed ratio, and conversion level of the reactants. − To attain the high yield of desirable product, the understanding of the reaction mechanism is required. Several mechanisms have been proposed: the hydroxymethylene mechanism [MC­(OH)­CH 3 ], the alkyl mechanism (M–CH 2 CH 3 ), the alkenyl mechanism (M–CHCH 2 ), and the alkylidene mechanism (MCHCH 3 ) .…”