Oxygen Reduction Reaction Mechanisms on Al-Doped X-Graphene (X = N, P, and S) Catalysts in Acidic Medium: A Comparative DFT Study
Oxygen Reduction Reaction Mechanisms on Al-Doped X-Graphene (X = N, P, and S) Catalysts in Acidic Medium: A Comparative DFT Study
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DOI：
10.1021/acs.jpcc.6b09674
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发表时间：
2016-11-24
影响因子：
3.7
通讯作者：
Lee, Jae Sung
中科院分区：
文献类型：
--
作者：
Bhatt, Mahesh Datt;Lee, Guensik;Lee, Jae Sung
应用密度泛函理论，对酸性介质中掺铝的X-石墨烯(X=N，P，S)电催化剂的氧还原反应机理进行了比较研究。为了研究铝掺杂的X-石墨烯(X=N、P和S)的催化性能，我们计算了O-2、O、OH、OH、H2O和H_2O_2的吸附性能。我们还考察了ORR过程中的2E和4E途径，即每个ORR步骤的吸附能。计算结果表明，每个Al掺杂的X-石墨烯催化剂(X=N、P和5)都遵循4E转移路径，具有良好的放热反应能量。我们观察到，在酸性环境中，掺铝的N-石墨烯和掺铝的P-石墨烯都比掺铝的S-石墨烯催化剂更有利于通过4E途径增强和稳定的ORR。这种分析在聚合物电解质燃料电池阴极应用中选择合适的催化剂是非常有用的。
Density functional theory (DFT) is applied to study the oxygen reduction reaction (ORR) mechanisms on Al-doped X-graphene (X = N, P, and S) electrocatalyst in acidic medium in a fuel cell cathode comparatively. In order to study the catalytic properties of Al-doped X-graphene (X = N, P, and S), we calculate the adsorption properties of the ORR intermediates O-2, O, OOH, OH, H2O, and H2O2. We also examine 2e and 4e pathways during the ORR process in terms of adsorption energy of each ORR step. Our calculated results reveal that each Al-doped X-graphene (X = N, P, and 5) catalyst follows a 4e transfer pathway with favorable (exothermic) reaction energies. We observe that both Al-doped N-graphene and Al-doped P-graphene are energetically more favorable than Al-doped S-graphene catalysts for enhanced and stable ORR via 4e pathways in an acidic environment. Such analysis is quite useful in choosing the appropriate catalyst in applications of a polymer electrolyte fuel cell cathode.