Dong Chengyuan, Wang Xinyao, Zhu Zhipeng, Zhan Changhong, Lin Xin, Bu Lingzheng, Ye Jinyu, Wang Yucheng, Liu Wei, Huang Xiaoqing
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Nano and Heterogeneous Materials Center, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
J Am Chem Soc. 2023 Jul 19;145(28):15393-15404. doi: 10.1021/jacs.3c03317. Epub 2023 Jul 10.
Designing efficient formic acid oxidation reaction (FAOR) catalysts with remarkable membrane electrode assembly (MEA) performance in a direct formic acid fuel cell (DFAFC) medium is significant yet challenging. Herein, we report that the monoclinic-phased platinum-tellurium nanotrepang (-PtTe NT) can be adopted as a highly active, selective, and stable FAOR catalyst with a desirable direct reaction pathway. The -PtTe NT exhibits the high specific and mass activities of 6.78 mA cm and 3.2 A mg, respectively, which are 35.7/22.9, 2.8/2.6, and 3.9/2.9 times higher than those of commercial Pt/C, rhombohedral-phased PtTe NT (-PtTe NT), and trigonal-phased PtTe NT (-PtTe NT), respectively. Simultaneously, the highest reaction tendency for the direct FAOR pathway and the best tolerance to poisonous CO intermediate can also be realized by -PtTe NT. More importantly, even in a single-cell medium, the -PtTe NT can display a much higher MEA power density (171.4 mW cm) and stability (53.2% voltage loss after 5660 s) than those of commercial Pt/C, demonstrating the great potential in operating DFAFC device. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy jointly demonstrate that the unique nanostructure of -PtTe NT can effectively optimize dehydrogenation steps and inhibit the CO intermediate adsorption, as well as promote the oxidation of noxious CO intermediate, thus achieving the great improvement of FAOR activity, poisoning tolerance, and stability. Density functional theory calculations further reveal that the direct pathway is the most favorable on -PtTe NT than -PtTe NT and -PtTe NT. The higher activation energy to produce CO and the relatively weaker binding with CO of -PtTe NT result in the better CO tolerance. This work achieves remarkable FAOR and MEA performances of advanced Pt-based anodic catalysts for DFAFCs via a phase engineering strategy.
在直接甲酸燃料电池（DFAFC）介质中设计具有卓越膜电极组件（MEA）性能的高效甲酸氧化反应（FAOR）催化剂意义重大但极具挑战性。在此，我们报道单斜相铂碲海参状纳米管（-PtTe NT）可作为一种具有理想直接反应路径的高活性、选择性和稳定性的FAOR催化剂。-PtTe NT分别展现出6.78 mA cm²和3.2 A mg⁻¹的高比活性和质量活性，分别比商业Pt/C、菱方相PtTe NT（-PtTe NT）和三角相PtTe NT（-PtTe NT）高35.7/22.9、2.8/2.6和3.9/2.9倍。同时，-PtTe NT还能实现直接FAOR路径的最高反应倾向以及对有毒CO中间体的最佳耐受性。更重要的是，即使在单电池介质中，-PtTe NT也能展现出比商业Pt/C更高的MEA功率密度（171.4 mW cm⁻²）和稳定性（5660 s后电压损失53.2%），证明其在运行DFAFC装置方面具有巨大潜力。傅里叶变换红外光谱和X射线光电子能谱共同表明，-PtTe NT独特的纳米结构可有效优化脱氢步骤并抑制CO中间体吸附，同时促进有害CO中间体的氧化，从而实现FAOR活性、抗中毒性和稳定性的大幅提升。密度泛函理论计算进一步揭示，直接路径在-PtTe NT上比在-PtTe NT和-PtTe NT上更有利。-PtTe NT产生CO的活化能较高且与CO的结合相对较弱，导致其具有更好的CO耐受性。这项工作通过相工程策略实现了用于DFAFC的先进铂基阳极催化剂卓越的FAOR和MEA性能。
