柠檬酸络合溶解铁粉绿色合成费托催化剂

A green synthetic route to fischer-tropsch catalysts by complexing and dissolving iron powder with citric acid

柠檬酸是目前世界上产量最大的生物质有机酸之一,应用十分广泛。文章以还原铁粉为铁源,柠檬酸为多齿络合剂和碳源,采用氨水强化柠檬酸络合溶解能力的策略,使其能较快溶解铁粉形成均相的溶胶-凝胶络合物,再经过原位炭化直接获得碳包覆核壳型铁基费托催化剂。在催化剂的费托合成反应性能测试中,使用柠檬酸直接溶解铁粉制备得到的催化剂表现出了优异的催化活性和稳定性,CO转化率达到99.2%,C_(5+)烃类选择性为53%,经过168 h的稳定性测试后,CO转化率仍稳定保持在97.3%以上。柠檬酸络合法可以避免硝酸铁等铁盐的使用,以及铁盐还原过程中易爆和有害气体的产生,具有更加绿色安全的特点,该合成方法为催化剂的绿色安全生产提供了一种新思路。

Citric acid is one of the most productive biomass organic acids in the world and has been widely used.In this paper,we used reduced iron powder as iron source,citric acid as multidentate ligand and carbon source,and used ammonia to enhance the coordination solubilization ability of citric acid to iron powder,so that it could quickly form a homogeneous complex sol-gel,which was then carbonized to obtain carbon-coated core-shell iron-based Fischer-Tropsch catalyst.In the performance test,the catalyst synthesized by direct dissolution of iron powder with citric acid exhibited remarkable catalytic activity and stability,giving the CO conversion of 99.2%,C_(5+)hydrocarbon selectivity of 53%,and the CO conversion activity was stably kept above 97.3%for a time on stream of 168 h.The citric acid coordination method is greener and safer,which avoid the use of iron salts such as ferric nitrate,and the risk of explosion and toxic gases in the reduction process of iron salts.This synthesis method provides a new idea for the green and safe production of catalysts.