掺氮纳米炭球担载高分散钯纳米催化剂的制备及其苯甲醇氧化性能(英文)

负载型贵金属纳米催化剂中的金属纳米粒子易发生团聚或流失,因此提高金属活性组分的分散性和稳定性很重要。我们报道了一种制备高分散钯纳米催化剂的方法,通过浸泡法将氯钯酸前驱体负载到苯并噁嗪聚合物上,再经过惰性气氛一步热解得到纳米炭球担载钯催化剂.催化剂性能通过温和条件下苯甲醇氧化反应进行评价.经过500℃热处理制备的催化剂,从TEM图可以看出Pd纳米粒子均匀分散在载体上,尺寸大小约为3 nm,这是由于载体和钯活性组分的配位作用有利于提高钯纳米粒子的分散性和稳定性.通过调控金属负载量及负载时间,尽可能地实现活性组分分布在载体外表面,制备的催化剂上最高TOF为690 h-1.此催化剂同时具有较好的循环稳定性,失活后的催化剂经过200℃焙烧即可实现再生.

Uniformly dispersed Pd nanoparticles on nitrogen-doped carbon nanospheres for aerobic benzyl alcohol oxidation

Maintaining the dispersion and stability of supported metals is still an important issue for solid catalysts that suffer from aggregation or leaching. We report an easy procedure for the preparation of Pd nanoparticles supported on carbon nanospheres by the direct pyrolysis of the metal precursor impregnated on polybenzoxazine‐based polymer nanospheres. The complexation interaction be‐tween the metal and support was beneficial for the dispersion and stability of the Pd nanoparticles. Pd nanoparticles with an average size of 3 nm were uniformly dispersed on the carbon nanospheres after a thermal treatment at 500 °C under argon flow. The catalyst was evaluated for aerobic benzyl alcohol oxidation under mild conditions without using a base additive. In order to get mostly outer surface Pd nanoparticles, the catalyst preparation conditions were investigated by varying the metal loading and loading time. The highest catalytic activity reached a TOF of 690 h–1 when the catalyst was prepared under the optimized conditions. The catalyst also showed good recyclability and can be easily regenerated by calcination at 200 °C.