Fine-Tuning the Electronic Structure of Dealloyed PtCu Nanowires for Efficient Methanol Oxidation Reaction
Kaili Wang, Danyang Huang, Yichi Guan, Feng Liu, Jia He, Yi Ding
Abstract
Designing highly efficient and durable electrocatalysts for methanol oxidation reaction (MOR) plays a decisive role in the commercialization of direct methanol fuel cells (DMFCs). Compared with commercial Pt/C catalysts, fine-tuning the electronic structure of electrocatalysts to reduce the adsorption energy of CO while at the same time increasing the adsorption energy of OH is beneficial to improving the activity of MOR. Herein, ultrastable self-supported PtCu nanowires (NWs) with abundant Cu-vacancies have been developed, wherein the CO adsorption energy is weakened by doping of Cu elements and the OH adsorption energy is strengthened by the vacancy defect through dealloying. The well-designed PtCu NWs exhibit an outstanding performance for the MOR, with a specific activity 7.5 times higher than that for the commercial Pt/C catalyst, which transcends most electrocatalysts’ performance currently. Moreover, the stability of PtCu electrocatalysts is greatly improved over 1 h owing to a “non-CO” pathway for MOR. Further DMFC tests present a 2 times higher power density than that of commercial Pt/C, and the PtCu integrated DMFC also presents a higher stability for 24 h, transcending most Pt-based anode catalysts of DMFCs.