丁烷氧化脱氢Ni-Zn双金属催化剂:氧移动性与催化性能

Ni-Zn bimetallic catalysts for oxidative dehydrogenation of butane:Oxygen mobility and catalytic performance

针对丁烷氧化脱氢反应中NiO催化剂性能差的问题,提出采用溶胶凝胶法制备一系列Ni-Zn双金属催化剂,考察了不同Zn含量下催化丁烷氧化脱氢的性能。结合氢气程序升温还原(H2-TPR)、程序升温氧化还原(TPRO)及X射线光电子能谱(XPS)等表征手段,研究了催化剂的氧化还原能力对催化性能的影响。结果表明,NiZn_(0.5)催化剂的性能最好。Zn元素的加入提高了催化剂的氧移动性,体现在催化剂氧容量增大及催化剂上晶格氧的补充能力增强。NiZn_(0.5)催化剂由于具有最大的氧容量和最高的氧补充速率,在反应过程中催化剂上的氧空位更容易被填补。此外,双组分催化剂改善了单一NiO易结焦的问题。

A series of Ni-Zn bimetallic catalysts were prepared by the sol-gel method to improve the catalytic performance of NiO catalyst for oxidative dehydrogenation(ODH)of butane,and the effect of Zn contents on the ODH reaction was investigated.H2 temperature-programmed reduction(H2-TPR),temperature-programmed re-oxidation(TPRO)and X-ray photoelectron spectroscopy(XPS)were used to study the redox ability and catalytic performance of catalysts.The results revealed that the NiZn_(0.5) catalyst exhibited the best catalytic performance.The addition of Zn improved the oxygen mobility of the catalysts,which was reflected in the increased oxygen capacity of the catalyst and the enhanced lattice oxygen replenishment on the catalyst.NiZn_(0.5) catalyst had the largest oxygen capacity and the highest oxygen replenishment rate,making it easier for oxygen vacancies on the catalyst to be filled during the reaction process.In addition,the bimetallic oxide catalysts improved the coking problem of NiO catalyst.