氮杂活性炭负载钯的制备及其在苯甲酸水相加氢中的应用

Highly active Pd nanoparticles on N-doped active carbon for the hydrogenation of benzoic acid in water

以双氰胺为氮源、廉价的活性炭为前驱体,合成氮含量易于调节的氮杂活性炭,并用于负载高分散的Pd纳米颗粒(Pd/NAC).在以水作溶剂的苯甲酸选择性加氢至环己基甲酸的反应中,Pd/NAC的催化活性是未掺杂活性炭(AC)负载Pd催化剂的6.7倍.表征发现:氮源的添加量可以调变活性炭表面氮的含量和种类,从而影响载体表面Pd纳米颗粒的分散性和电子结构,进而调变催化剂的催化活性.

N-doped active carbon （ NAC） has been produced through the thermal treatment of the mixture consisted of dicyandiamide as the nitrogen source and commercial active carbon as the precursor. The-prepared NAC materials are used as excellent supports for the anchored dispersion of Pd species to obtain Pd/NAC. This electron-deficient Pd catalyst affords 6 . 7 times activity as high as the undoped catalyst and shows excellent stability for the hydrogenation of benzoic acid to cyclohexane carboxylic acid in water. The characterizations disclosed that dicyandiamide amount could adjust the N content and N species on surface of NAC, the dispersion and electronic structrure of Pd NPs, and then influenced their catalytic performance deeply.