摘要
利用碳黑(Vulcan XC-72R)中加入硫酸钴和吡啶(Py)作为催化剂前驱体,经溶剂分散热处理构建了一类新型的高效氧还原CoPy/C复合催化剂.并运用循环伏安法(CV)和旋转圆盘电极(RDE)技术研究了不同Co含量的CoPy/C催化剂在碱性介质中对氧还原的电催化活性.结果表明:Co的存在对氧的催化剂活性位的形成有重要影响,800℃下所制备的10%Co30%Py/C(质量分数)复合催化剂表现出最佳的氧还原催化活性.以其制备的气体扩散电极在3.0 mol·L^(-1)KOH电解质溶液(O_2气氛)中0.014 V(相对于标准氧电极(RHE))即可产生明显的氧还原电流.同40%Py/C相比,10%Co30%Py/C催化氧还原的起峰电位正移了71 mV,同时表现出明显的极限扩散电流.在-0.16 V时电流密度达到最大值,电流密度为1.0 mA·cm^(-2),半波电位在-0.07 V.透射电镜分析表明所制备的碳黑载吡啶钴(10%Co30%Py/C)催化剂平均粒径为20 nm.
In this communication, we report a novel CoPy/C catalyst for the oxygen reduction reaction （ORR） in alkaline electrolyte using cobalt sulfate heptahydrate （COSO4 · 7H2O） and pyridine （Py） as the Co and N precursors supported on Vulcan XC-72R, followed by heat treatment in an inert atmosphere. Electrochemical performances were evaluated using cyclic voltammograms （CVs） and rotating disk electrode （RDE） technique in terms of its ORR activity as a function of Co content in the catalyst synthesis. Results show that the presence of Co in the CoPy/C catalyst greatly affects the formation of ORR catalytic active sites and that the best performing catalyst is 10%Co%30Py/C, which was synthesized at 800℃. In 3.0 mol. L-1 KOH, 10%Co30%Py/C （in 02） produces an obvious ORR current with an on-set potential at 0.014 V. Compared with the 40% Py/C the on-set potential of the 10% Co30% Py/C for oxygen reduction shifted positively by 71 mV （versus RHE （reversible hydrogen electrode）） and a well-defined limiting current plateau was achieved. Therefore, a maximum current density of 1.0 mA· cm-2 was obtained at-0.16 V with a half-wave potential of-0.07 V. Transmission electron microscopy （TEM） measurements show that the nanoparticles with a diameter of 20 nm are uniformly dispersed on Vulcan carbon （Vulcan XC-72R）.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2011年第10期2251-2254,共4页
Acta Physico-Chimica Sinica
基金
supported by the National Natural Science Foundation of China(21173039)
Pujiang Foundation of Shanghai,China(08PJ14096)
Natural Science Foundation of Shanghai Science and Technology Committee,China(09ZR1433300)
Opening Foundation of Zhejing Provincial Top Key Discipline,China(20110927)
Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China(2009(1001))
Shanghai Leading Academic Discipline Project Fund,China(B604)~~
