Yang Xiaotong, Yuan Qiang, Li Jingwei, Sheng Tian, Yao Ke Xin, Wang Xun
State-Local Joint Laboratory for Comprehensive Utilization of Biomass, Center for R&D of Fine Chemicals, College of Chemistry and Chemical Engineering, Guizhou University, Guiyang, Guizhou Province 550025, People's Republic of China.
Multi-scale Porous Materials Center, Institute of Advanced Interdisciplinary Studies & School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, People's Republic of China.
Nano Lett. 2023 Apr 26;23(8):3467-3475. doi: 10.1021/acs.nanolett.3c00535. Epub 2023 Apr 10.
Finding a high-performance low-Pt bipolar electrocatalyst in actual direct alcohol fuel cells (DAFCs) remains challenging and desirable. Here, we developed a crystalline PdPtCu@amorphous subnanometer Pd-Pt "dual site" layer core-shell structure for the oxygen reduction reaction (ORR) and alcohol (methanol, ethylene glycol, glycerol, and their mixtures) oxidation reaction (AOR) in an alkaline electrolyte (denoted D-PdPtCu). The prepared D-PdPtCu/C achieved a direct 4-electron ORR pathway, a full oxidation pathway for AOR, and high CO tolerance. The ORR mass activity (MA) of D-PdPtCu/C delivered a 52.8- or 59.3-fold increase over commercial Pt/C or Pd/C, respectively, and no activity loss after 20000 cycles. The D-PdPtCu/C also exhibited much higher AOR MA and stability than Pt/C or Pd/C. Density functional theory revealed the intrinsic nature of a subnanometer Pd-Pt "dual site" surface for ORR and AOR activity enhancement. The D-PdPtCu/C as an effective bipolar electrocatalyst yielded higher peak power densities than commercial Pt/C in actual DAFCs.
在实际的直接醇类燃料电池（DAFC）中找到一种高性能的低铂双极电催化剂仍然具有挑战性且令人期待。在此，我们开发了一种用于碱性电解质中氧还原反应（ORR）和醇类（甲醇、乙二醇、甘油及其混合物）氧化反应（AOR）的晶体PdPtCu@非晶亚纳米Pd-Pt“双位点”层核壳结构（记为D-PdPtCu）。制备的D-PdPtCu/C实现了直接的4电子ORR途径、AOR的完全氧化途径以及高CO耐受性。D-PdPtCu/C的ORR质量活性（MA）分别比商业Pt/C或Pd/C提高了52.8倍或59.3倍，并且在20000次循环后没有活性损失。D-PdPtCu/C在AOR MA和稳定性方面也比Pt/C或Pd/C高得多。密度泛函理论揭示了亚纳米Pd-Pt“双位点”表面增强ORR和AOR活性的内在本质。作为一种有效的双极电催化剂，D-PdPtCu/C在实际的DAFC中产生的峰值功率密度高于商业Pt/C。
