电催化剂
催化作用
石墨氮化碳
密度泛函理论
氮化物
化学
铂金
兴奋剂
碳纤维
氮化碳
材料科学
物理化学
无机化学
纳米技术
计算化学
电化学
复合数
电极
复合材料
有机化学
光催化
光电子学
图层(电子)
作者
Feng He,Kai Li,Cong Yin,Ying Wang,Hao Tang,Zhijian Wu
出处
期刊:Carbon
[Elsevier BV]
日期:2016-12-26
卷期号:114: 619-627
被引量:88
标识
DOI:10.1016/j.carbon.2016.12.061
摘要
Designing the low cost, long durability and high efficient substitutes for platinum (Pt) electrocatalyst to facilitate ORR is significant for the large-scale commercial application of fuel cells. In this work, single Pd atoms supported on graphitic carbon nitride (i.e., Pd/g-C3N4) with different Pd coverages acting as electrocatalyst for ORR is investigated by using the density functional theory calculations. Our study shows that the doping of Pd atoms can effectively decompose H2O2, leading to a four-electron mechanism via the sequential hydrogenation of *O2 giving *O+*H2O on Pdx/g-C3N4 (x = 1–4). With the increase of Pd coverages, the energy barriers increase in the rate determining step, which are 0.39 eV, 0.63 eV, 0.68 eV and 2.61 eV for Pdx/g-C3N4 (x = 1–4), respectively. This implies that Pdx/g-C3N4 (x = 1–3) have lower energy barrier than Pt (calculated value 0.80 eV), showing high ORR activity compared with Pt. The oxidized Pd2/g-C3N4 (i.e., Pd2/g-C3N4−O) shows similar ORR activity to Pd2/g-C3N4, but with different rate determining step. The working potentials are also discussed for the studied catalysts. Especially, the working potential for Pd2/g-C3N4 is up to 0.60 V, comparable to calculated value 0.73 V for Pt/Cu(100).
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