载体对Au/BN催化剂苯甲醇选择性氧化性能的影响

Effect of support factors on the selective catalytic oxidation of benzyl alcohol over Au/BN catalyst

  • 摘要: 本研究以三种不同结构特点的氮化硼(BN)充当载体,负载Au纳米颗粒进行苯甲醇选择性氧化反应,发现载体的结晶性、比表面积对活性相Au的尺寸具有显著影响。Au/BN500的比表面积是晶化程度高的Au/BN600、Au/BN700催化剂的四倍以上。相较于Au/BN700而言,Au/BN500催化剂Au纳米颗粒具有更好的分散性以及更小的粒径(13 vs. 3.2 nm),且Au/BN500的活性是其他催化剂的两倍,但其催化活性在5 h以内有30%左右的流失。

     

    Abstract: The selective oxidation of primary alcohols represents a premier route for the synthesis of aldehydes as intermediates of multiple commercial fine chemicals such as drugs and perfumes. In particular, catalytically selective oxidation of primary alcohol in use of oxygen is of great interest, owning to its high efficiency, solvent-free, and easy separation. As such, choosing this route to pursue desired atomic economy has been an essential topic of common concern in both academic and industrial circles in recent years. Boron nitride with graphite like structure is a new catalyst developed in recent years, which has the characteristics of stability and good thermal conductivity. In this contribution, three kinds of boron nitride (BN) with different structural characteristics were used as carriers to support Au nano metal for selective oxidation of benzyl alcohol. It is found that the crystallinity and specific surface area of the carriers have a great influence on the size of active phase Au. The specific surface area of ​​Au/BN500 is four times higher than those of the Au/BN600 and Au/BN700. Compared with Au/BN700, Au/BN500 catalyst has better dispersion and smaller particle size (13 vs. 3.2 nm). The catalytic activity of Au/BN500 is about twice as much as those of the other two, and about 30% activity is lost within 5 h. The results in this paper provide enriched experimental and theoretical references for rational design and development of novel high-performance boron nitride-based oxidative dehydrogenation catalysts.

     

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