晶格氧用于甲烷氧化制合成气的研究 —氧化铁的氧化还原性能

Study on Lattice Oxygen Used in the Conversion of Methane to Synthesis Gas——Redox Performance of Fe_2O_3 Catalyst

制备了氧化铁催化剂 ,对其进行了程序升温实验 (O2 - TPD、空气 - TPO和 CH4- TPR)和不同温度下的多次CH4-空气脉冲循环反应 ,并对催化剂进行了 XRD表征 .研究结果表明 ,Fe2 O3不仅具有较高的稳定性 ,还具有良好的氧化还原性能 ,可使 CH4氧化为 CO2 和 H2 O.在 75 0～ 85 0℃的范围内 ,Fe2 O3 具有良好的提供晶格氧的能力 ;在 90 0℃以上 ,供氧速度减慢 ,供氧和补氧能力明显降低 .XRD测试结果表明 ,高于 90 0℃时 ,脉冲空气不能将与脉冲 CH4反应后的氧化铁氧化为 Fe2 O3晶相 。

Fe\-2O\-3 as an oxygen storage compound was prepared and its redox performance was investigated using O\-2 temperature programmed desorption (O\-2\|TPD), air temperature programmed oxidation (air\|TPO), CH\-4 temperature programmed reduction (CH\-4\|TPR) and pulse reaction techniques. It was found that Fe\-2O\-3 is a good redox catalyst. The pulse reaction results show that methane can be completely oxidized by lattice oxygen of Fe\-2O\-3 to carbon dioxide and water, while the lower\|valenced iron oxide can be reoxidized by air to Fe\-2O\-3 in the temperature range of 750~850 ℃. Once the temperature exceeds 900 ℃, the amount of available lattice oxygen of Fe\-2O\-3 drastically reduced due to the sintering of iron oxide.