Novel Ptni Nanoflowers Regulated by a Third Element (Rh, Ru, Pd) as Efficient Multifunctional Electrocatalysts for Orr, Mor and Her

Abstract

A series of tri-functional nanoflower (NF) catalysts with numerous nanodendrites (Pt3NiRh, Pt3NiRu, Pt3NiPd, Pt3Ni, and Pt2Ni2Rh NFs) were synthesized by introducing Rh, Ru, and Pd into Pt-Ni nanoflowers, aiming at accelerating the sluggish kinetics of oxygen reduction reaction (ORR), methanol oxidation reaction (MOR), and hydrogen evolution reaction (HER). The as-prepared catalysts displayed superior anti-poisoning ability and excellent activity due to uniform morphology and good dispersibility. Their electrochemical characterization revealed that Pt3NiRh NFs showed the highest mass activity (2.336 A mgPt-1) and specific activity (3.128 mA cm-2) toward ORR, close to 10.6 and 4.6 times higher than the values measured on Pt/C (46.7%). As for MOR, mass and specific activities of Pt3NiRh NFs were 2.016 A mgPt-1) and 2.623 mA cm-2, far exceeded the values on commercial Pt/C. Moreover, HER activity of Pt3NiRh NFs outperformed commercial Pt/C. This work is valuable to develop promising multi-functional catalysts with enhanced-activity and anti-poisoning ability.

Keywords: multifunctional electrocatalysis, trimetallic Pt-Ni-M alloy nanoflowers, Density functional theory.