P促进Pd/C高效催化甲酸制氢的研究

Improved Highly Efficient Hydrogen Production from Formic Acid on a Pd/C Catalyst Doped by Phosphorus

以次亚磷酸钠(NaH2PO2)为还原剂,成功地制备出一种新型高效的Pd-P/C催化剂,其对甲酸-甲酸钠混合液分解制氢具有较高催化活性.经过优化后得到的3%Pd-P/C催化剂,在30℃,反应液甲酸和甲酸钠浓度比为1∶5,总浓度为4mol/L条件下,前1h平均转化频率可达565h-1,该Pd-P/C催化剂的催化活性是传统的以NaBH4还原制得的Pd/C催化剂活性的3.5倍.联合谱学表征结果表明,在Pd粒子的形成生长过程中,P的掺入提高了Pd纳米粒子的分散性,减少了粒子的团聚,最终得到了粒径较小的Pd粒子,从而极大地提高了催化剂的活性.动力学研究表明Pd-P/C催化剂催化甲酸分解的反应活化能为18.63kJ/mol,相比以NaBH4还原所得催化剂(反应活化能为26.69kJ/mol),反应活化能更低.

A potent phosphorus-doped Pd nanocatalyst （Pd-P/C） for hydrogen generation from the formic acid （FA） sodium for-mate （SF） mixtures has been successfully prepared via the reduction of Nail2 PO2. Over this 3% Pd-P/C catalyst, the turn over fre- quency （TOF） of 565 h 1 was observed for a FA-SF mixture with a FA/SF concentration ratio of 1：5 and the total concentration of 4 mol/L at 30℃. Compared with Pd/C synthesized with a NaBH4 reduction method,the activity of Pd-P/C is 3.5 times as much. The results of the catalyst characterization demonstrated that the modification with P during the formation and growth of particles resulted in the well-dispersed fine Pd nanoparticles on carbon and enhanced the catalytic performance of the resulted catalyst. Kinetic studies showed that its reaction activation energy was 18.63 kJ/mol when utilizing Pd-P/C,much lower than utilizing Pd/C as a cata lyst （reaction activation energy of 26.69 kJ/mol）.