纳米级Au/C催化剂的制备及其DBFC单池性能

Preparation of nano Au/C catalysts and their performance as a direct borohydride fuel cell electrode

采用金溶胶负载法分别在CNTs、Vxc-72R炭黑和ECP 600JD科琴炭黑上负载了平均粒径约为5.0nm且尺寸分布均匀的纳米金颗粒,考察了酸处理对炭载体的影响及不同Au/C催化剂对BH4-电催化活性的影响。结果显示:经过酸处理三种炭载体的表面亲水性提高,其中CNTs的BET比表面积提高,而Vxc-72R和ECP 600JD的BET比表面积降低。炭载体负载纳米Au的能力与其BET比表面积密切相关。对炭载体进行酸处理可大幅度提高Au/C催化剂对BH4-的电催化性能,其中金负载在经酸处理的ECP 600JD炭黑上显示出最佳的电催化性能。

Au/C catalysts were prepared by immobilizing the gold sol having a mean particle size of 5.0 nm with a quite narrow size distribution on carbon nanotubes（CNTs）,Vxc-72R or ECP 600JD carbon black.Electrocatalytic activities of different Au/C catalysts with and without acid treatment（first with concentrated HCl then with concentrated HNO3） for the carbon supports for BH-4 oxidation were investigated.The hydrophilicity of all carbon supports and the Brunauer-Emmett-Teller（BET） surface area of CNTs increased,but the BET surface area of Vxc-72R or ECP 600JD decreased after the acid treatment.The Au loading on the carbon supports was closely related to the BET surface area of the supports.Acid treatment of the carbon supports was also an important factor for improving the electrocatalytic activity of the catalysts.Au supported by the acid-treated ECP 600JD exhibited the best electrocatalystic activity for BH-4 oxidation as an anode catalyst for the direct sodium borohydride fuel cell.