ACS Sustainable Chemistry & Engineering | 2019
Oxygen Reduction Reaction over PtFeM (M = Mo, V, W) Alloy Electrocatalysts: Role of the Compressive Strain Effect on Pt
Abstract
The high level loading requirement of platinum and the sluggish oxygen reduction kinetics—catalyzed by platinum-based electrocatalysts—create major bottlenecks for cost-effective application of fuel cell technology. Herein, ternary PtFeM (M = Mo, V, W) alloy electrocatalysts with different levels of compressive strain on Pt were systematically prepared using the method of impregnation-reduction, post-treated at high temperatures. The physicochemical characterization displays that these elements (Fe, Mo, V, and W) are crucial for inducing a compressive strain effect on Pt and improving the oxygen reduction activity. In all the as-prepared electrocatalysts, a remarkable enhancement of ∼20-fold in mass activity at 0.9 V, with respect to commercial Pt/C, is witnessed on Pt25Fe70Mo5/C that possesses the moderately compressive strain effect on Pt and the suitable electronic ligands. After accelerated testing (30k cycles of cyclic voltammetry), Pt25Fe70Mo5/C exhibits ∼threefold activity compared to pristine Pt/C...