Ce_(0·67)Zr_(0·33)O_2对CH_4燃烧催化剂Fe_2O_3/Al_2O_3的改性作用

Effect of Ce_(0.67)Zr_(0.33)O_2 on Catalytic Properties of Fe_2O_3/Al_2O_3 Catalyst for Methane Combustion

固定n(Ce)/n(Zr)比为0·67/0·33,用共沉淀法制得一系列CeO2-ZrO2-Al2O3固溶体.采用这些固溶体作载体,以Fe2O3为活性组分,用浸渍法制备了一系列催化剂.BET结果显示,将适量Ce0·67Zr0·33O2引入到Al2O3载体中有助于催化剂保持较高的比表面积.TPR结果显示,载体中引入适量的Ce0·67Zr0·33O2可以改善催化剂的氧化还原性能.XRD结果表明,Fe2O3在CeO2-ZrO2-Al2O3载体上呈现出良好的分散状况,老化前后催化剂的晶相结构基本无明显变化.特别是当载体中m(Ce0·67Zr0·33O2)∶m(Al2O3)的值为1∶2时,Fe2O3/CeO2-ZrO2-Al2O3催化剂在甲烷催化燃烧中显示出最佳的催化性能和抗高温老化性能.

In order to find a kind of low-cost and high-capability catalyst for methane combustion, a series of CeO2-ZrO2-Al2O3 solid solution, in which the content of Ce0.67Zr0.33O2 and Al2O3 were different, were prepared by co-precipitation method. Fe2O3 -based catalysts supported on the solids were prepared by impregnation. Their characterizations and catalytic activity were tested by BET, TPR, XRD methods after being calcined at 600 ℃ or aging in water gas at 1 000 ℃. It is indicated that addition of Stoichiometric Ce0.67Zr0.33O2 into the Al2O3 support improved the catalytic capability of the Fe2O3/CeO2-ZrO2-Al2O3 catalyst, increased the catalyst＇s specific surface areas, promoted its redox ability, and stabilized its crystal structure. In particular, when m （ Ce0. 67Zr0. 33 O2 ） ： m （ Al2 O3 ） was 1 ： 2, the Fe2 O3/CeO2-ZrO2 -Al2 O3 catalyst possessed the best catalytic capability and the best resistance to aging at high temperature.