Low‐dose Ir‐doped TiO ₂ supported Pt‐Co bimetallic nanoparticles: A highly active and CO‐tolerant electrocatalyst towards methanol oxidation reaction

Abstract

Summary Highly stable and cost‐effective electrocatalysts are of importance in regulating energy conversion efficiency and commercial feasibility of direct methanol fuel cells (DMFCs). So far, integrating transition metals into Pt‐based catalysts to enhance their catalytic performances for methanol electro‐oxidation reaction (MOR) at the anode of DMFCs has received significant interest. This study witnessed the first time of depositing Pt3Co1 alloy nanoparticles (NPs) on robust Ti0.9Ir0.1O2 supports utilizing a modified reduction method that used NaBH4 as a reducing agent in the absence of surfactants or stabilizers. This novel combination not only reduces the usage of costly and easily‐deactivated Pt but also significantly improves catalytic activity and poisoning tolerance for MOR. Regarding electrocatalytic performance, the onset potential and the mass activity of the Pt3Co1/Ti0.9Ir0.1O2 catalyst are ~0.1 V vs NHE and 316.16 mA/mgPt, respectively, which are 4.5‐fold lower and 1.5‐fold higher than the corresponding figures for the commercial Pt/C (E‐TEK) catalyst, ~0.45 vs NHE and 206.83 mA/mgPt, indicating superior catalytic activity and CO‐tolerance of the former over the latter. Furthermore, the superior anti‐poisoning ability and stability of the Pt3Co1/Ti0.9Ir0.1O2 catalyst are demonstrated by its 2.2‐fold higher If/Ib ratio in MOR and lower degradation rate in the 60‐min chronoamperometry (CA) and 3000‐cycle scanning tests than the Pt/C counterpart. These enhancements could be abscribed to synergistic influence between the Pt‐Co alloy NPs and the robust Ti0.9Ir0.1O2 support. The addition of Co into the catalyst to promote removal of Pt‐poisoning species as well as the use of highly corrosion‐resistant Ir‐doped TiO2 as a catalyst support play a decisive role in boosting electrochemical behaviors of the Pt3Co1/ Ti0.9Ir0.1O2 catalyst. Generally, the success of this work in synthesizing high‐performance Pt3Co1/Ti0.9Ir0.1O2 catalyst could serve as groundwork for further development of TiO2‐based material supported bimetallic catalysts for applications in the electrochemical catalysis field.

Strategic Fabrication of Simplified Ternary Alloy PtxCuyCoz Nanoparticles Supported on Carbon-Free Ti0.7W0.3O2 Nanomaterials for Methanol Oxidation Reaction

“…The I f / I b ratio represents the resistance of the catalyst to CO. It can be calculated as the forward current density I f divided by the inverse current density I b . In this study, Pt 6 CuCo/Ti 0.7 W 0.3 O 2 had the greatest I f / I b value with a ratio of ∼1.85, greater than Pt 2 CuCo/Ti 0.7 W 0.3 O 2 (∼1.67) > Pt 4 CuCo/Ti 0.7 W 0.3 O 2 (∼1.66), while the lowest was PtCuCo/Ti 0.7 W 0.3 O 2 (∼1.32).…”

Anchoring Ultrasmall Pt Nanocrystals onto Carbon Nanohorn-Decorated 3D Graphene Networks to Boost Methanol Oxidation Reaction

“…In this context, direct methanol fuel cell (DMFC), as an emerging energy-conversion system, has shown great application potentials in the fields of electric vehicles, mobile electronic equipment, and aerospace due to its high energy-conversion efficiency, low working environment temperature, miniature size, and low pollution emission [4,5]. However, as the key semireaction of DMFC, the methanol oxidation reaction (MOR) has intrinsically slow electrochemical kinetics that has seriously hindered the commercial use of DMFC devices [6,7]. In recent years, enormous efforts have been devoted to the design and fabrication of efficient MOR catalysts, which are expected to accelerate the reaction efficiency and thereby boost the overall output power of DMFC [8,9].…”