Synthesis of Structurally Ordered Pt₃Ti and Pt₃V Nanoparticles as Methanol Oxidation Catalysts

Abstract

Structurally ordered Pt3Ti or Pt3V intermetallic nanoparticle catalysts with ultrasmall particle sizes have never been successfully synthesized. Herein, we present a KCl-nanoparticle method to successfully provide such compounds. These two catalysts show enhanced catalytic activity and stability for methanol oxidation compared to pure Pt.

Synthesis of Pt3Y and Other Early–Late Intermetallic Nanoparticles by Way of a Molten Reducing Agent

“…11,13,16 In our hands, YCl 3 could not be reduced with KEt 3 BH at room temperature in THF, and if PtCl 4 was included in the reaction, only pure Pt was observed. This is consistent with literature: an Y 3+ complex with two Et 3 BH -anions coordinated has been characterized.…”

“…For example, nBuLi can be added to Au nanoparticles to form Au 3 Li, 10 and KEt 3 BH is strong enough to reduce TiCl 4 with PtCl 4 together in THF to form Pt 3 Ti nanoparticles after annealing. 11 Another challenge is the high temperature sometimes needed to achieve the structural ordering of an IM phase rather than simply an alloy, the IM often being crucial to catalytic activity. [11][12] This rules out organic surfactants during the annealing step, as they will Scheme 1.…”

“…11 Another challenge is the high temperature sometimes needed to achieve the structural ordering of an IM phase rather than simply an alloy, the IM often being crucial to catalytic activity. [11][12] This rules out organic surfactants during the annealing step, as they will Scheme 1. Process scheme for the synthesis of Pt 3 Y nanoparticles.…”

Carbon-Supported Ordered Pt-Ti Alloy Nanoparticles as Durable Oxygen Reduction Reaction Electrocatalyst for Polymer Electrolyte Membrane Fuel Cells

“…A few groups have reported that carbon-supported ordered Pt-Ti alloy nanoparticles could be prepared via wet chemical approaches, unlike Pt alloys with Y, Sc, or Zr [12,13]. Ti 3+ can be reduced by strong reducing agents such as sodium naphthalenide [14] and potassium triethylborohydride [15]. The DiSalvo group prepared ordered Pt 3 Ti alloy nanoparticles by a thermal annealing step at 700 o C in a KCl matrix before depositing them onto carbon supports [15].…”

“…Ti 3+ can be reduced by strong reducing agents such as sodium naphthalenide [14] and potassium triethylborohydride [15]. The DiSalvo group prepared ordered Pt 3 Ti alloy nanoparticles by a thermal annealing step at 700 o C in a KCl matrix before depositing them onto carbon supports [15]. Ding et al prepared carbonsupported ordered Pt 3 Ti nanoparticles by decomposing Pt and Ti salts deposited onto carbon supports at 850 and 950 o C under a H 2 /N 2 (1:10 v/v) atmosphere [16].…”