Catalytic Ru containing Pt3Mn nanocrystals enclosed with high-indexed facets: Surface alloyed Ru makes Pt more active than Ru particles for ethylene glycol oxidation

摘要

Tuning the surface property of Pt based nanocrystals at the atomic level is of vital significance to meet superior electrocatalytic performance criteria. In this work, a new strategy to advance fundamental surface study on Pt based nanocrystals is addressed by implanting foreign metals as "active auxiliaries" onto the surface of Pt based nanocrystals to engineer a stable structured catalyst. Under the guidance of this concept, the Ru component was selected as "active auxiliary" to construct Ru containing Pt3Mn catalysts by doping the isolated Ru atoms (Pt3Mn-Ru) and Ru nanoparticles (Pt3Mn@Ru) onto surface layer of Pt3Mn concave nanocubes (CNCs). Strikingly, the Pt3Mn-Ru CNCs showed the most optimal catalytic activity, durability and CO anti-poisoning ability toward ethylene glycol oxidation reaction (EGOR). The specific activity of Pt3Mn-Ru CNCs is 1.32 mA cm(-2), which is 1.47 and 3.07 times higher than Pt3Mn@Ru CNCs (0.90 mA cm(-2)) and pure Pt3Mn CNCs (0.43 mA cm(-2)). The results of in situ Fourier transform infrared spectroscopy experiments revealed that Pt3Mn-Ru CNCs were more in favor of C-C bond cleavage of EG and rapid oxidation/removal of intermediate poisonous COads. Furthermore, the theoretical calculations revealed that the Pt3Mn-Ru CNCs possessed a lower reaction barrier (1.69 eV) for oxidation of COads assisted by adsorbed OHads species, and an energy-favorable position (2.88 angstrom) for reaction between COads and OHads. This work disclosed a new tactics to develop a novel structured catalyst in possession of excellent electrocatalytic performance, which provided a promising methodology for designing Pt-based nanoparticles as efficient fuel cell catalysts.