Ni/CeO2催化剂的金属-载体界面调控及其低温化学链甲烷干重整性能研究

Regulation of metal-support interface of Ni/CeO2 catalyst and the performance of low temperature chemical looping dry reforming of methane

  • 摘要: 本研究合成了四种CeO2形貌的Ni/CeO2催化剂(纳米棒、纳米立方体、纳米八面体和纳米多面体),并探讨了催化剂低温化学链甲烷干重整反应的结构依赖性。材料表征表明,Ni物种高度分散在CeO2载体表面,部分Ni离子进入CeO2晶格,从而引起氧空位的增加。化学链干重整性能测试结果表明,棒状结构Ni/CeO2催化剂表现出最高的还原性,具有最多氧空位和最高储氧能力。多面体状Ni/CeO2催化剂的结构为形状不规则的约10.3 nm的CeO2纳米单晶,具有较大的比表面积和较高的还原性,表现出低温甲烷反应活性,在550 ℃低温化学链甲烷干重整中显示最高的氧化还原活性和循环稳定性。本研究为设计高效的金属/CeO2催化剂提供了一种新策略,有望促进铈基催化剂在化学链技术中应用。

     

    Abstract: Interface regulation is an effective strategy to improve the interaction between carrier and active metal center, which can improve the catalytic activity and oxygen storage capacity of the catalysts. In this paper, Ni/CeO2 catalysts supported on CeO2 with different morphologies (nanorods, nanocubes, nanoctahedrons and nanopolyhedrons) were synthesized. The structure dependence of the catalysts for the low temperature chemical looping dry reforming of methane (CL-DRM) was investigated. The characterization results showed that Ni species were highly dispersed on the surface of CeO2 carrier, and some Ni ions entered the CeO2 lattice, resulting in the increase of oxygen vacancies. The Ni/ceria-rods catalyst had the highest reducibility, the most oxygen vacancies and the highest oxygen storage capacity. The irregular CeO2 nano single crystal of about 10.3 nm in the Ni/ceria-polyhedra led to high specific surface area and high reducibility which exhibited the highest redox activity and redox stability in low-temperature chemical looping dry reforming of methane at 550 ℃. This study provided a new strategy for the design of efficient metal/CeO2 catalysts, which was expected to promote the application of cerium-based catalysts in chemical looping technology.

     

/

返回文章
返回