微通道反应器中使用氢气氧气直接合成双氧水

Direct Synthesis of H_(2)O_(2)from H_(2)and O_(2) at Ambient Temperature in a Microchannel Reactor

采用微通道反应器在常温下使用氢气氧气直接合成双氧水,对Pd/AC、Pd/CNF、Pd/Al_(2)O_(3)等3种使用不同载体和制备方式的催化剂的活性进行评价.结果表明,比表面积较高且中孔发达的催化剂,以及未经热处理的催化剂的催化活性更高.另外,在微通道反应器中反应存在诱导期,在诱导期内催化活性随反应时间逐渐上升并达到一个平台,表明纯粹的Pd^(0)对于直接合成H_(2)O_(2)的催化活性很低.反应条件的研究结果表明,直接合成H_(2)O_(2)反应的最佳H_(2)/O_(2)进气比为0.5.

In this article,direct synthesis of H_(2)O_(2)from H_(2)andO_(2)was conducted in a microchannel reactor at ambient temperature.The catalytic performances of three kinds of catalysts,Pd/AC,Pd/CNF,Pd/Al_(2)O_(3),which used different supports and were prepared by different methods were tested.The experiment results indicated that the catalyst with high specific surface areas and dominated mesopores and without treatment in high temperatures usually exhibited a higher catalytic activity because of the high mass transfer rate and metal dispersion.Moreover,an induction period was detected for the experiments conducted in the microchannel reactor.The catalytic activity gradually increased and finally reached a plateau.This phenomenon strongly suggested that the catalytic activity of the pure Pd^(0)was quiet poor for the direct synthesis of H_(2)O_(2).The further results of the researches on the reaction conditions showed that the optimal inlet ration of H_(2)/O_(2)was 0.5.