高热处理提高了低CuO含量的CuO / CeO2催化剂对CO氧化的催化活性,Catalysis Science & Technology

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高热处理提高了低CuO含量的CuO / CeO2催化剂对CO氧化的催化活性
Catalysis Science & Technology ( IF 4.4 ) Pub Date : 2020-07-02 , DOI: 10.1039/d0cy00757a
Jihang Yu _{1,

2,

3,

4,

5} , Qiangsheng Guo _{1,

2,

3,

4,

5} , Xiuzhen Xiao _{1,

2,

3,

4,

5} , Haifang Mao _{1,

2,

3,

4,

5} , Dongsen Mao _{1,

2,

3,

4,

5} , Jun Yu _{1,

2,

3,

4,

5}

Affiliation

通过浸渍法制备了一系列不同CuO负载量（0.5、1、3和5 wt％）的CuO / CeO ₂催化剂，并测试了CO的总氧化。通过各种结构和质地检测来表征样品XRD，N ₂吸附，TEM-EDS，H ₂ -TPR，XPS和原位DRIFTS等技术。出乎意料的是，在高温（800°C）下煅烧的低CuO负载量（0.5–3 wt％）样品表现出比在500°C下煅烧的样品更好的催化性能，并且在500°C和800随着铜含量的增加，温度降低。相反，当CuO的负载量达到正常值（5重量％）时，CuO / CeO ₂低温煅烧（500°C）的催化剂比在800°C下煅烧的催化剂活性稍好。结果表明，对于低CuO含量（0.5–3 wt％）的催化剂，较高温度的煅烧（800°C）可以促进配位不饱和铜原子的形成并增加活性Cu的含量，从而导致比在500°C下煅烧的活性更高。但是，当CuO含量达到5重量％时，该效果被抑制。配位不饱和的铜原子以及Cu ⁺被证实是CuO / CeO ₂催化剂的主要活性中心。

"点击查看英文标题和摘要"

High-heat treatment enhanced catalytic activity of CuO/CeO2 catalysts with low CuO content for CO oxidation

A series of CuO/CeO₂ catalysts with different CuO loadings (0.5, 1, 3, and 5 wt%) were prepared by an impregnation method, and tested for the total oxidation of CO. The samples were characterized by various structural and textural detection techniques including XRD, N₂ sorption, TEM-EDS, H₂-TPR, XPS, and in situ DRIFTS. Unexpectedly, the low CuO loading (0.5–3 wt%) samples calcined at high temperature (800 °C) exhibited better catalytic performance than those calcined at 500 °C, and the catalytic activity gap between the catalysts calcined at 500 °C and 800 °C shrunk with the increase of copper content. In contrast, when the loading amount of CuO reached a normal value (5 wt%), the CuO/CeO₂ catalyst with low temperature calcination (500 °C) obtained a slightly better activity than that calcined at 800 °C. The results showed that, for the catalysts with low CuO content (0.5–3 wt%), the higher temperature calcination (800 °C) can promote the formation of the coordinatively unsaturated copper atoms and increase the content of active Cu species, resulting in a higher activity than those calcined at 500 °C. But this effect was suppressed when the CuO content reached 5 wt%. The coordinatively unsaturated copper atoms, as well as Cu⁺, were confirmed to be the main active sites of the CuO/CeO₂ catalysts.

更新日期：2020-08-05

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