The fabrication of Pt–Pb alloy networks with high-density micropores by dealloying for enhanced oxygen reduction activity

Abstract

Porous Pt-based nanomaterials possess intriguing properties for various important applications due to their abundant exposed active sites and highly accessible surfaces. Importantly, the pore size is a key factor that determines its specific applicability. With the advances of fabrication strategies, Pt-based nanomaterials with a variety of unique pore structure including mesopores and macropores have been extensive reported. However, so far, few effective methods have been reported to prepare the Pt-based nanomaterials with high-density micropores. In this work, we reported a facile method to prepare the high-density microporous Pt–Pb NWs via a chemical etching strategy by using the intermetallic PtPb networks (NWs) as the starting material. After dealloying, a large amount of microporous and defects were successfully introduced into the MP-PtPb NWs. The microporous networks can not only increase the active area both on the exterior and interior surface, but also provide efficient mass transfer and electron mobility for reactant molecules. As a result, the mass activity exhibited by MP-PtPb NWs catalyst is 0.83 A mg−1Pt, which is 5.8 and 1.9 times than that of commercial Pt/C and IM-PtPb NWs. Besides, even after 10,000 cycles of accelerated durability test, the MP-PtPb NWs and IM-PtPb NWs exhibit comparable drop of ∼10% in mass activity, against a big decrease of 46% for commercial Pt/C. We believe this work provides an efficient strategy to prepare metallic catalysts with high-density microporous nanomaterials for catalysis.