Abstract |
THe methanation of carbon dioxide was studied over bimetallic nickel-5f block element oxides, 2NiO center dot ThO2 and 2NiO center dot UO3. The catalysts were prepared by two approaches: controlled oxidation under dry air using intermetallic binary compounds (AnNi(2); An=Th, U) as precursors and by a modified sol-gel method. The best results were those obtained using the thorium-based catalysts that present activities and selectivities higher than those measured over two reference catalysts. To the best of our knowledge, this is one of the few times that bimetallic nickel-5f block element oxides were tested for the methanation of carbon dioxide and their behaviour was a complete, or not, surprise. The catalysts present also unusual and long stability in the gaseous stream and with activities 10-30 times superior to that measured over a commercial 5wt.-\%Rh catalyst supported on alumina, they clearly merit an opportunity and further studies. |