Effect of Support on Oxygen Reduction Reaction Activity of Supported Iron Porphyrins
Effect of Support on Oxygen Reduction Reaction Activity of Supported Iron Porphyrins
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DOI：
10.1021/acscatal.1c04871
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发表时间：
2022-01-04
期刊：
影响因子：
12.9
通讯作者：
Gewirth，Andrew A.
中科院分区：
文献类型：
--
作者：
Hua，Qi;Madsen，Kenneth E.;Gewirth，Andrew A.
本文报道了铁卟啉在不同载体上的酸中氧还原反应（ORR）活性。当Fe卟啉吸附在XC 72（一种石墨碳）上时，活性很高（E1/2= 0.34 V，n = 3.8），而当卟啉吸附在MoS 2（E1/2=-0.15 V，n = 2.2）或g-C3 N4（E1/2=-0.24 V，n = 3.1）上时，活性要低得多。电子顺磁共振（EPR），X射线吸收精细结构（XAFS），和磁力测量显示的电子结构周围的铁中心是相同的所有三个支持。只有负载在XC 72上的Fe卟啉在其ORR活性中表现出pH依赖性。这一观察结果，加上XC 72相对于其他载体的亲水性增加，表明载体-电解质相互作用控制ORR活性。改性MoS 2以增加其亲水性导致更高活性的ORR催化剂。
We report the oxygen reduction reaction (ORR) activity in acid of an Fe porphyrin on different supports. While the activity is high (E1/2= 0.34 V vs RHE withn= 3.8) when the Fe porphyrin is adsorbed on XC72 (a graphitic carbon), this activity is much lower when the porphyrin is adsorbed on either MoS2(E1/2= −0.15 V vs RHE withn= 2.2) or g-C3N4(E1/2= −0.24 V vs RHE withn= 3.1). Electron paramagnetic resonance (EPR), X-ray absorption fine structure (XAFS), and magnetometry measurements show the electronic structure around the Fe center is the same for all three supports. Only the Fe porphyrin supported on XC72 exhibits a pH dependence in its ORR activity. This observation, coupled with the increased hydrophilicity of XC72 relative to the other supports, suggests that the support-electrolyte interaction controls the ORR activity. Modification of MoS2to increase its hydrophilicity results in a more active ORR catalyst.