Jia Xiuquan, Ma Jiping, Xia Fei, Xu Yongming, Gao Jin, Xu Jie
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Nat Commun. 2018 Mar 2;9(1):933. doi: 10.1038/s41467-018-03358-x.
Controlling the reaction selectivity of a heterobifunctional molecule is a fundamental challenge in many catalytic processes. Recent efforts to design chemoselective catalysts have focused on modifying the surface of metal nanoparticle materials having tunable properties. However, precise control over the surface properties of base-metal oxide catalysts remains a challenge. Here, we show that green modification of the surface with carboxylates can be used to tune the ammoxidation selectivity toward the desired products during the reaction of hydroxyaldehyde on manganese oxide catalysts. These modifications improve the selectivity for hydroxynitrile from 0 to 92% under identical reaction conditions. The product distribution of dinitrile and hydroxynitrile can be continuously tuned by adjusting the amount of carboxylate modifier. This property was attributed to the selective decrease in the hydroxyl adsorption affinity of the manganese oxides by the adsorbed carboxylate groups. The selectivity enhancement is not affected by the tail structure of the carboxylic acid.
控制异双功能分子的反应选择性是许多催化过程中的一项基本挑战。近期设计化学选择性催化剂的努力主要集中在修饰具有可调性质的金属纳米颗粒材料的表面。然而，精确控制贱金属氧化物催化剂的表面性质仍然是一个挑战。在此，我们表明，在羟基醛与氧化锰催化剂的反应过程中，用羧酸盐对表面进行绿色修饰可用于调节氨氧化反应对所需产物的选择性。在相同反应条件下，这些修饰将羟基腈的选择性从0提高到了92%。通过调整羧酸盐改性剂的用量，可以连续调节二腈和羟基腈的产物分布。这种性质归因于被吸附的羧酸盐基团使氧化锰的羟基吸附亲和力选择性降低。选择性的提高不受羧酸尾部结构的影响。
