CO2催化氢化研究--REY负载双金属催化剂的催化作用

用高压釜实验评价了用离子交换法制备的负载于ＲＥＹ和ＺＳＭ－５分子筛上的多种过渡金属对ＣＯ２加氢合成醇和甲烷化的催化活性。实验结果表明，双金属催化剂的活性按下列顺序降低，ＣＯ２甲烷化；Ｒｕ＞ＮｉＲｕ＞ＮｉＰｄ＞ＮｉＩｒ；合成醇：ＮｉＣｕ＞Ｎｉ＞ＮｉＭｎ＞ＮｉＣｏ。用２％Ｒｕ／ＲＥＹ催化剂，在４７３Ｋ，３．９ＭＰａ，ＣＯ２／Ｈ２＝１／５，反应时间２０ｈ条件下，７６％的ＣＯ２转化为甲烷。反应温度，压力和

Catalytic Hydrogenation of Carbon Dioxige and Characterrization of Rey Supported Bimetal Catalysits

This work primarily concerned with the REY and ZSM -5 supported bimetal catalysts for the hydrogenation of carbon dioxide by autoclave experiments. The catalytic properties of the catalysts were tested and the activities decreased in the following order: for carbon dioxide methanation, Ru/RE Y > NiRu/REY > NiPd/REY > Ni-Ir/REY;for synthesis of alcohols:NiCu/REY>Ni/REY > NiMn/REY > NiCo/REY. The conversion of carbon dioxide to methane is up to 76% over the 2% Ru/REY catalyst at 473 K,3. 9 MPa,ratio of hydrogen gas/carbon dioxide = 5, in a 20 hour run. The influence of reaction conditions on the NiCu/REY indicated that the selectivity for alcohols is high from 443 - 473 K. The increase of temperature and pressure of the reaction lowered the selectivity for alcohols and increased the selectivity for methane and carbon monoxide. Experiments for the investigation of the effect of solvents on carbon dioxide hy-drogenation indicated that poloar solvents such as triethy-lamine promoted the reaction more effectively than less polar solvents. FT -IR spectra indicated that the intensity of the 1400 and 1437 cm-1bands of the REY supported catalysts are higher than that of ZSM -5 supported catalysts. The peaks at 1400,1437 and 1636 cm-1 might be assigned to the absorption of NH3 coordinated to the metal ion center in the form of Ni(NH3)6]2+ and/or Ni (NH3)5NO3]+.