Nanoporous PtCo and PtNi alloy ribbons for methanol electrooxidation

Nanoporous (NP) PtCo and PtNi alloy ribbons with predetermined bimetallic compositions are easily fabricated by one step of mild dealloying, which are characterized by uniform three-dimensional bicontinuous network architecture with the ligament size as small as 3 nm. Compared with E-TEK Pt/C catalyst, the as-made NP-PtCo(Ni) alloys exhibit superior specific activity with the lower peak potential and enhanced CO-tolerance toward methanol electrooxidation. More importantly, these nanomaterials also show much higher structure stability with little loss of the electrochemical surface area of Pt upon 5000 potential cycles in acid solution. X-ray photoelectron spectroscopy and DFT calculations revealed that alloying with Co or Ni modifies the electronic structure of Pt with the downshift of Pt d-band center, thus resulting in the improved methanol oxidation activity and decreased CO poisoning.

Graphical abstractNanoporous PtCo and PtNi alloy ribbons, characterized by open three-dimensional bicontinuous network structure, were easily fabricated by selectively dealloying PtCo(Ni)Al source alloys, which exhibit greatly enhanced catalytic activity, CO-tolerance, and structure stability toward methanol electrooxidation compared with Pt/C catalyst.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Nanoporous (NP) PtCo(Ni) alloys are fabricated with small structure size at 3 nm. ► NP-PtCo(Ni) alloys show unique specific activity for methanol electrooxidation. ► NP-PtCo(Ni) alloys show enhanced CO-tolerance and improved catalytic durability. ► NP-PtCo(Ni) alloys exhibit superior structure stability compared with E-TEK Pt/C. ► Alloying with Co(Ni) weakens Pt–CO bonding with the decrease of Pt d-band center.