陈四国,薛云,张文贵,李莉,丁炜,齐学强,魏子栋.聚苯胺增强 Pt / C 催化剂活性和稳定性研究[J].表面技术,2015,44(1):56-63.
CHEN Si-guo,XUE Yun,ZHANG Wen-gui,LI Li,DING Wei,QI Xue-qiang,WEI Zi-dong.Enhancement of Durability and Activity of Pt/ C Catalyst by Polyaniline[J].Surface Technology,2015,44(1):56-63 |
| 聚苯胺增强 Pt / C 催化剂活性和稳定性研究 |
| Enhancement of Durability and Activity of Pt/ C Catalyst by Polyaniline |
| 投稿时间：2014-12-22 修订日期：2015-01-20 |
| DOI： |
| 中文关键词: 燃料电池 氧还原反应 电催化剂 稳定性 聚苯胺 |
| 英文关键词:fuel cells oxygen reduction reaction electrocatalyst stability polyaniline |
| 基金项目:国家重点基础研究发展计划(973 计划) 资助项目(2012CB215500);国家自然科学基金资助项目(21376283,21376284,51272297,21276291) |
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| Author | Institution |
| CHEN Si-guo | Chongqing University, College of Chemistry and Chemical Engineering, Chongqing Key Lab of Chemical Process for Clean-energy and Resource Utilization, Chongqing 400044, China |
| XUE Yun | Chongqing University, College of Chemistry and Chemical Engineering, Chongqing Key Lab of Chemical Process for Clean-energy and Resource Utilization, Chongqing 400044, China |
| ZHANG Wen-gui | Chongqing High-energy Battery Enterprises Engineering Research Center(EnerSys Chongqing Huada Batteries Company limited), Chongqing 400900, China |
| LI Li | Chongqing University, College of Chemistry and Chemical Engineering, Chongqing Key Lab of Chemical Process for Clean-energy and Resource Utilization, Chongqing 400044, China |
| DING Wei | Chongqing University, College of Chemistry and Chemical Engineering, Chongqing Key Lab of Chemical Process for Clean-energy and Resource Utilization, Chongqing 400044, China |
| QI Xue-qiang | Chongqing University, College of Chemistry and Chemical Engineering, Chongqing Key Lab of Chemical Process for Clean-energy and Resource Utilization, Chongqing 400044, China |
| WEI Zi-dong | Chongqing University, College of Chemistry and Chemical Engineering, Chongqing Key Lab of Chemical Process for Clean-energy and Resource Utilization, Chongqing 400044, China |
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| 中文摘要: |
| 目的 制备一种具有高稳定性和高催化活性的 Pt/ C@ PANI“核/ 壳冶结构催化剂。 方法 利用原位化学氧化聚合法制备聚苯胺修饰 Pt/ C@ PANI“核/ 壳冶结构催化剂,采用循环伏安加速寿命实验,结合电化学活性表面积、氧还原活性、X-射线光电子能谱和透射电镜,考察所制备催化剂的活性和稳定性,通过密度泛函理论探究 PANI 增强 Pt/ C 催化剂活性和稳定性的量子化学本质原因。 结果 电化学测试表明,Pt/ C@ PANI 催化剂的催化活性与聚苯胺包覆层含量和厚度密切相关,Pt/ C@ PANI(30% )催化剂具有最好的催化活性,其质量比活性和比表面比活性分别为商业化 Pt/ C 催化剂的 1. 6 和 1. 8 倍。 加速寿命实验表明,Pt/ C@ PANI(30% )催化剂具有很好的稳定性,经过 1500 圈 CV 扫描后,其电化学活性表面积仅下降了 30% ,而商业化 Pt/ C 催化剂降低了 83% 。 理论计算表明,PANI 将电子转移给载体 C,导致自身空穴增加,PANI 部分氧化,导电性增强;PANI 的存在使 Pt/ C@ PANI 体系的 HOMO 能级升高,减小了与氧气分子 LUMO 能级的差异,有利于电子从催化剂 HOMO 转移到氧分子的 LUMO 轨道,使得氧容易得到电子;PANI 吸附后,Pt 原子 d 带中心显著降低,利于中间物种的脱附,催化活性更高。 结论 PANI包覆层抑制了 Pt 纳米粒子在载体表面的迁移、团聚长大和溶解/ 再沉积,有效地解决了 Pt/ C 催化剂的Ostwald 肿大,催化剂的活性和稳定性得到显著提升。 |
| 英文摘要: |
| Objective To prepare a Pt/ C@ PANI core-shell catalyst with high catalytic activity and durability. Methods The polyaniline (PANI)-decorated Pt / C@ PANI core-shell catalyst was prepared by in situ chemical oxidation polymerization method. The stability and activity of the Pt / C@ PANI catalyst prepared were evaluated using accelerated durability test (ADT), along with the monitoring of electrochemical surface area ( ECSA), oxygen reduction reaction ( ORR) activities, X-ray photoelectron spectrometer (XPS) and transmission electron microscopy (TEM), and the density functional theory (DFT) calculations were carried out to investigate the essential reasons for the enhanced catalytic activity and durability of Pt / C catalyst by PANI. Results The experimental results demonstrated that the activity for the ORR strongly depended on the PANI content and the thickness of the PANI shell, and that the prepared Pt / C@ PANI(30% ) catalyst with 5 nm PANI exhibited a Pt mass and a specific activity of nearly 1. 6 and 1. 8 times higher than those of the commercial Pt / C catalysts. The accelerated stability test showed that the ECSA of Pt / C@ PANI(30% ) catalyst was only decreased by ~ 30% , whereas the Pt / C catalysts lost ~ 83% of the initial ECSA after 1500 cycles of CV scanning. The DFT calculations disclosed that the number of holes in PANI increased with the electrons transfer from PANI to the supporting C, which caused partial oxidation of PANI and thus strengthened the electric conductivity of PANI. The lifted HOMO energy level and lowered d band center of Pt / C@ PANI compared with Pt / C were beneficial to the electron transfer between Pt / C@ PANI and O2 due to the reduced gap between the Pt / C@ PANI HOMO and the oxygen LUMO, and the desorption of intermediate species on the surface of the catalysts and releasing fresh catalytic sites for the subsequent reaction. Conclusion The PANI-decorated layer could enhance the Pt-support interaction and help to inhibit Pt dissolution / re-deposition, aggregation and ripening, which effectively solve the problem of Ostwald enlargement of the Pt / C catalyst, resulting in significant enhancement in the activity and stability of the catalyst. |
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