MoS2-Coated Ni3S2 Nanorods with Exposed {110} High-Index Facets As Excellent CO-Tolerant Cocatalysts for Pt: Ultradurable Catalytic Activity for Methanol Oxidation

Methanol oxidation reaction (MOR) efficiency is lowered by poor COads-tolerance and structural stability of Pt-based catalysts. Herein, single crystal Ni3S2 nanorods (with exposed {110} high-index facets) coated with MoS2 particles are grown on nickel foam (MoS2/Ni3S2-nrs/NF) as a low-loading Pt support/cocatalyst (Pt, 0.5 wt %), which not only enhances anti-COads poisoning capacity but also extremely improves the structure stability of the catalyst. Pt/MoS2/Ni3S2-nrs/NF catalyst exhibits a mass activity of 805.4 mA mg(pt)(-1), which is 1.97 times higher than that of commercial Pt/C (10 wt %). It also shows an excellent cyclic durability with 4.6% decline (Pt/C, 40.2%) after 28 h. Electrochemcial tests and theoretical calculations (DFT) reveal that the excellent MOR activity and durability of Pt/MoS2/Ni3S2-nrs/NF are primarily attributed to the close binding effects among Pt, MoS2, and Ni3S2-nrs. Theoretical calculations show that, when Pt nanoparticles deposit on the preconstructed MoS2/Ni3S2-nrs hybrid, they preferentially attach to the single crystal Ni3S2-nrs rather than MoS2 particles. These heterostructures can offer sufficient active sites in radial direction, which energetically promote the charge transfer along axial dimension. Sufficient Mo-S-x edge (interface) sites facilitate OHads generation from H2O decomposition. Meanwhile, OHads can fast react with/eliminate CO-species on MoS2/Ni3S2-nrs attracted from Pt active-sites. Therefore, MoS2/Ni3S2-nrs/NF as a promising MOR support/cocatalyst provides unique perspectives for high-efficient utilization of Pt.