电沉积制备Pd_xCo_y/rGO纳米复合催化剂及其对甲酸电催化性能研究

Pd_xCo_y/rGO Nanocomposite Electrocatalysts Synthesized by Electrodeposition for Formic Electrooxidation in Acid Medium

利用电沉积法在石墨烯(rGO)表面制备了具有不同钯(Pd)钴(Co)比的PdCo纳米复合催化剂。采用场发射扫描电镜、X-射线能谱和傅里叶红外等方法对所制备的不同比例催化剂进行了表征。结果表明,所制备电催化剂中金属元素的比例接近于前驱体溶液中金属离子浓度之比;相比Pd/rGO和Co/rGO催化剂,Pd_xCo_y/rGO二元催化剂的粒径较小,且颗粒粒径分布均匀;在0.5 mol/L硫酸电解液中研究了催化剂对甲酸的电催化性能,发现在所有催化剂中,Pd_1Co_3/rGO具有最大的电化学活性面积,对甲酸电氧化具有最高的活性和最好的稳定性,证明所制备的Pd_1Co_3/rGO纳米复合催化剂在直接甲酸燃料电池中具有潜在的应用价值。

PdxCoy/rGO nanocomposite catalysts with different Pd:Co ratios were prepared by electrodeposition. The structure and morphology of the prepared catalysts were characterized by field emission scanning electron microscope, X-ray energy dispersive spectroscopy and Fourier transform infrared. The results indicate that the compositions of the as-synthesized electrocatalysts are close to the metal ion concentration ratios in the precursors. The metal particle si zes of the Pdx Coy/rGO binary electrocatalysts are smaller than those of Pd/rGO and Co/rGO monometallic electrocatalysts. The size distributions of the Pd x Coy/rGO binary electrocatalysts are more even in comparison with those of the Pd/rGO and Co/rGO monometallic electrocatalysts. The Pd1 Co3/rGO nanocomposite catalyst exhibits the largest electrochemical active surface area in 0.5 mol/L H2SO4 electrolyte, and shows the highest electrocatalytic activity and the best stability for formic acid electrooxidation. The results indicate that the as prepared Pd1Co3/rGO nanocomposite catalyst by electrodeposition is very promising for application in direct formic acid fuel cell.