Preparation And Properties Of Supported Ruthenium-contained Catalyst For Water-gas Shift Reaction

In this thesis, a series of supported catalysts for water-gas shift (WGS) reaction was prepared by loading active species on the supporters (MgAl₂O₄ spinel) with large specific surface area. The supported catalysts manifest high catalytic activity and better thermal stability than traditional catalysts due to the high dispersion of active species.The properties of supported WGS catalysts have been studied by using XRD, TEM, and DSC-TGA etc. The results show that lanthanum oxide cannot enter the lattice of Fe₃O₄, and act as electronical promoters. The preparation method of ruthenium nanoparticles has great effect on catalytic activity of supported ruthenium catalysts, sample prepared from ethylene glycol reduction have superior activity to sample prepared by NaBH₄ reduction. And the smaller the size of ruthenium nanoparticles, the better catalytic activity and the lower light-off temperature obtained. Catalysts prepared from composite nanoparticles have higher catalytic activity than supported only ruthenium catalysts, due to electronical effect the core to the shell.Catalyst FRL/MA-2 have the same activity as commercial Fe-Cr WGS catalysts B117 and better thermal stability; Catalysts R/MA-5and RL/MA-3 have high activity, CO conversion of ≥85% (at 350℃, S/G=1, SV=2000h^-1) were obtained. And they can be performed well under low steam/gas ratio and high space velocities conditions. Catalysts Fe₂O₃-Ru/MA prepared from composite nanoparticles show low light-off temperature (120 V) and high catalytic activity on WGS reaction, CO conversion of ≥97.4% (at 300℃, S/G=1, SV=2000h^-1) were obtained.