Ni-Fe/La_2O_3-ZrO_2在乙醇水蒸气重整制氢反应中的性能

The performance of Ni-Fe/La_2O_3-ZrO_2 catalyst in hydrogen production from ethanol steam reforming

用草酸盐沉淀法制备La2O3-ZrO2复合氧化物载体,用浸渍法制备Ni-Fe/La2O3-ZrO2催化剂;用X射线衍射和程序升温氧化技术表征催化剂;研究了乙醇水蒸气重整反应中催化剂的活性,针对催化剂组成和反应温度对乙醇转化率及产物分布的影响进行了讨论;分析了催化剂在723K至773K温区失活的原因。结果表明,催化剂具有四方晶相骨架,在乙醇水气重整反应中,催化剂的活性组分是零价态的镍,铁氧化物是助剂。催化剂的抗积碳能力与Ni/Fe比值密切相关,催化剂表面保持一定量铁氧化物有利于消除积碳;(4Ni1Fe)4(2La8Zr)催化剂对乙醇水气重整有最好的催化性能,其在523-873K温度范围内没有出现失活现象,823K时乙醇转化率达到100%,具有较好的催化活性和稳定性。

La2O3-ZrO2composite oxide support was prepared by oxalate precipitation method and Ni-Fe/La2O3-ZrO2 catalysts were prepared by impregnation. The catalysts were characterized by means of XRD and TPO. The activity of catalysts in ethanol steam reforming was studied, also the effects of the catalyst composition and reaction temperature on ethanol conversion and product distribution were discussed, and the inactivation phenomenon of catalyst under the temperature ranging from 723K to 773K was analyzed. The results show that the catalysts were remarkable tetragonal phase, and the active phase and assistant existed in catalysts during the reforming reaction are Ni elementary substance and iron oxide, respectively. The resistance to carbon is closely related to the Ni/Fe ratio, and the iron oxide maintained on catalyst surface contributes to the eliminating of carbon deposition. The （4Nil Fe） 4 （2La8Zr）catalyst with no inactivation phenomenon between 523-873 K exhibits best catalytic activity and stability in ethanol steam reforming,over which ethanol conversion is 100% under the situation of 823K.