Research On Photothermal Fischer-tropsch Synthwsis Performance Based On Semiconductor And Bimetallic Composite Oxide

Due to the growing global demand for liquid hydrocarbon fuels,it is of great economic importance to convert carbonaceous resource-derived syngas（CO+H₂）into clean fuels and valuable chemicals through Fischer-Tropsch Synthesis.The traditional FTS product carbon chain increases according to the polymer mechanism,the single product selectivity is low,follows the Anderson-Schulz-Flory（ASF）distribution,which largely limits its industrial application.In order to solve the above issues,a new idea is to introduce illumination,so that the thermal field and the light source synergistically catalyze FTS.In this paper,a series of photothermal dual-response catalysts are designed to explore the Fischer-Tropsch performance under different catalytic conditions.The main research contents of this paper are as follows:（1）The Catalyst 3%Ru-TiO_2-X was prepared by using the liquid phase reduction impregnation method to load the active metal ruthenium with black titanium dioxide as carrier.After the introduction of visible light,the CO conversion increased from5.3%to 15.2%,with the C₅₊selectivity was 76.2%and zero carbon dioxide generation.（2）When the rare earth elements lanthanum（La）and yttrium（Y）were added to the catalyst 3%Ru-TiO_2-X,the catalytic activity was improved as a whole.After the addition of La,the CO conversion increased from 5.3%to 20.6%,and the selectivity of C₅₊also increased slightly from 75.7%to 77.7%.After the addition of Y,the selectivity of C₅₊increased from 75.7%to 83.5.%,CO conversion also increased slightly.After the introduction of light,the CO conversion increased again,and the selectivity of short-chain hydrocarbons in the product increased slightly.In general,the addition of the adjuvant facilitates the Fischer-Tropsch synthesis reaction and is detrimental to the product distribution of the photothermal reaction.（3）The composite of ZnO and ZnCr₂O₄ was prepared by co-precipitation method,and then hydrogen-fired to obtain a ZnCrOx catalyst with a partially reduced surface,which can activate H₂ and CO molecules by itself.After examining the photothermal Fischer-Tropsch synthesis performance,it was found that when the ratio of the two is 1:1,both the Fischer-Tropsch activity and the photothermal Fischer-Tropsch activity can simultaneously achieve the highest CO conversion and the C₅₊selectivity,and the carbon dioxide selectivity was the lowest.（4）The ZnCrOx catalyst system increased the CO conversion by 33-55%under the condition of keeping the C₅₊selectivity almost unchanged after the introduction of different wavelengths of light,and the increase in CO conversion after introduction of visible light is greater than the introduction of ultraviolet light.