Stimulation of Electro-oxidation Catalysis by Bulk-Structural Transformation in Intermetallic ZrPt₃ Nanoparticles

Abstract

Although compositional tuning of metal nanoparticles (NPs) has been extensively investigated, possible control of the catalytic performance through bulk-structure tuning is surprisingly overlooked. Here we report that the bulk structure of intermetallic ZrPt3 NPs can be engineered by controlled annealing and their catalytic performance is significantly enhanced as the result of bulk-structural transformation. Chemical reduction of organometallic precursors yielded the desired ZrPt3 NPs with a cubic FCC-type structure (c-ZrPt3 NPs). The c-ZrPt3 NPs were then transformed to a different phase of ZrPt3 with a hexagonal structure (h-ZrPt3 NPs) by annealing at temperatures between 900 and 1000 °C. The h-ZrPt3 NPs exhibited higher catalytic activity and long-term stability than either the c-ZrPt3 NPs or commercial Pt/C NPs toward the electro-oxidation of ethanol. Theoretical calculations have elucidated that the enhanced activity of the h-ZrPt3 NPs is attributed to the increased surface energy, whereas the stability of the catalyst is retained by the lowered bulk-free-energy.

Atomically ordered non-precious Co3Ta intermetallic nanoparticles as high-performance catalysts for hydrazine electrooxidation

“…Hideki et al found that both 150-nm NbPt 3 and 100-nm TaPt 3 intermetallic particles showed significant enhancement in catalytic activity and stability compared with Pt NPs 31,32 . Despite these obvious advantages, the works of the related early transition metal nano-intermetallic compounds are preliminary (e.g., Pt 3 Ti 28,29 , Pt 3 V 29 , ZrPt 3 30 , NbPt 3 31 , TaPt 3 32 , and Pt 3 Y 33 ) due to higher melting points, more oxyphilic nature and much more negative reduction potentials of these metals compared with late transition metals. Furthermore, non-precious early transition metal nano-intermetallics, to the best of our knowledge, have not yet been reported.…”

Intermetallic Pd3X (X= Ti and Zr) nanocrystals for electro-oxidation of alcohols and formic acid in alkaline and acidic media

“…54 mg of Vulcan carbon was added to the reaction mixture. The reaction mixture was then transferred to a stainless-steel pressure vessel and heated at 200°C in an oil bath for 2 h under an argon pressure of 0.5 MPa [34,35]. The product was then transferred to a centrifuge tube under an argon atmosphere.…”

“…Then, 30 ml of diglyme were added to the vessel, and the mixture was stirred for 20 min to dissolve the reactants. Next, 1 ml of super-hydride was added to the reaction mixture, which was heated at 200°C in an oil bath for 2 h under an argon pressure of 0.5 MPa [34,35]. The product was then transferred to a centrifuge tube under an argon atmosphere.…”

“…Thus, alloys of Pd with early d-metals are expected to exhibit performances close to or even better than that of Pt in various catalytic reactions. However, developing such alloys is challenging due to the highly oxyphilic nature of the early d-metal precursors [ 33 – 35 ]. Herein, we present our attempt to develop a new class of intermetallic nanocrystals consisting of Pd and early d-metals, or Pd 3 X (where X = Ti and Zr), in addition to detailed characterization of these catalysts.…”

Chemically Ordered Pt–Co–Cu/C as Excellent Electrochemical Catalyst for Oxygen Reduction Reaction

“…PtCo, PtFe, PtCu, and PtCr. [20][21][22][23][24][25][26][27][28] Recently, ternary nanoparticles have gained growing attention as promising catalysts to enhance catalytic performances by providing more possibilities to modify the crystal phase of existing PtM catalysts. [29][30][31][32][33] Introducing third metal elements to the present binary catalysts for catalytic materials has been used to achieve superior catalytic performances.…”