Doroftei Corneliu, Murariu Gabriel, Dobromir Marius
Science Research Department, Institute of Interdisciplinary Research, Research Center in Environmental Sciences for the North-Eastern Romanian Region (CERNESIM), Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi, Romania.
Physics, Chemistry and Environment Department, Faculty of Sciences and Environment, ''Dunarea de Jos'' University of Galati, 111 Street Domneasca, 800201 Galati, Romania.
Materials (Basel). 2025 Apr 29;18(9):2008. doi: 10.3390/ma18092008.
Porous nanocrystalline lanthanum perovskite La-Fe-O (LaFeO) powders were synthesized by the sol-gel self-combustion method, using polyvinyl alcohol as the colloidal medium. The perovskite structure of the material, without secondary phases, was obtained at a calcination temperature of 900 °C for 40 min. The obtained powder was tested for catalytic activity at moderate temperatures (50-550 °C) for ethanol, methanol, acetone, benzene, and Pb-free gasoline vapors. Catalytic combustion begins at quite low temperatures (60-200 °C), compared to normal combustion, and this can be attributed to the nanometric crystallites, the large specific surface area, and the presence of iron cations with different valences, Fe/Fe, resulting from the method we used to obtain the material. The degree of conversion reaches values of over 99% for acetone and ethanol vapors at a temperature of 270 °C and 310 °C, respectively, and over 97% for methanol vapors at a temperature of 330 °C. The degree of conversion for Pb-free gasoline and benzene reaches somewhat lower values, over 88% at much higher temperatures, 470 °C and 550 °C, respectively. The lanthanum perovskite catalyst, LaFeO, obtained by the presented preparation method, can be recommended for the combustion of acetone, ethanol, and methanol vapors. The performance of this catalyst is remarkable and can be compared to that of a catalyst containing noble metals in its composition.
采用溶胶-凝胶自燃烧法，以聚乙烯醇作为胶体介质，合成了多孔纳米晶镧系钙钛矿La-Fe-O（LaFeO）粉末。在900℃煅烧40分钟的条件下，获得了无第二相的材料钙钛矿结构。对所得粉末在中等温度（50-550℃）下对乙醇、甲醇、丙酮、苯和无铅汽油蒸汽的催化活性进行了测试。与正常燃烧相比，催化燃烧在相当低的温度（60-200℃）下就开始了，这可归因于纳米微晶、大比表面积以及由于我们制备该材料的方法而产生的不同价态铁阳离子Fe/Fe的存在。在270℃和310℃时，丙酮和乙醇蒸汽的转化率分别达到99%以上，在330℃时甲醇蒸汽的转化率达到97%以上。无铅汽油和苯的转化率略低，在分别为470℃和550℃的更高温度下超过88%。通过本文提出的制备方法获得的镧系钙钛矿催化剂LaFeO，可推荐用于丙酮、乙醇和甲醇蒸汽的燃烧。该催化剂的性能卓越，可与成分中含有贵金属的催化剂相媲美。
