Facile Synthesis of Composition‐Controlled Graphene‐Supported PtPd Alloy Nanocatalysts and Their Applications in Methanol Electro‐Oxidation and Lithium‐Oxygen Batteries

Abstract

A new and simple approach is reported for the synthesis of uniformly dispersed PtPd alloy nanocatalysts supported on graphene nanoplatelets (GNPs) (PtPd-GNPs) through the introduction of bifunctional materials, which can modify the GNP surface and simultaneously reduce metal ions. With the use of poly(4-styrenesulfonic acid), poly(vinyl pyrrolidone), poly(diallyldimethylammonium chloride), and poly(vinyl alcohol) as bifunctional materials, PtPd-GNPs can be produced through a procedure that is far simpler than previously reported methods. The as-prepared nanocrystals on GNPs clearly exhibit uniform PtPd alloy structures of around 2 nm in size, which are strongly anchored and well distributed on the GNP sheets. The Pt/Pd atomic ratio and loading density of the nanocrystals on the GNPs are controlled easily by changing the metal precursor feed ratio and the mass ratio of GNP to the metal precursor, respectively. As a result of the synergism between Pt and Pd, the as-prepared PtPd-GNPs exhibit markedly enhanced electrocatalytic performance during methanol electro-oxidation compared with monometallic Pt-GNP or commercially available Pt/C. Furthermore, the PtPd-GNP nanocatalysts also show greatly enhanced catalytic activity toward the oxygen reduction/evolution reaction in a lithium-oxygen (Li-O ) process, resulting in greatly improved cycling stability of a Li-O battery.

Ultralong PtPd Alloyed Nanowires Anchored on Graphene for Efficient Methanol Oxidation Reaction

“…Then Pd-OH and Pt-CO could be reacted to release CO 2 and simultaneously regain the metal activity. [45,46] In addition, the mass activity of physically mixed PtPd NWs + graphene (520 mA mg À 1 metal ), PtPd/graphene-1 (727 mA mg À 1 metal ) and PtPd/graphene-2 (603 mA mg À 1 metal ) are less than PtPd NWs/ graphene, indicating that both synthesized process and Pt/Pd molar ratio could affect the morphology and MOR activity of the final products and PtPd NWs/graphene with optimized structure exhibits a superior MOR activity. When the graphene support is substituted by Vulcan XC-72R (labeled as PtPd/ carbon, Figure S9b), some PtPd NWs are loaded on the carbon, along with more agglomerated PtPd NWs.…”

Pt/NiO Microsphere Composite as Efficient Multifunctional Catalysts for Nonaqueous Lithium–Oxygen Batteries and Alkaline Fuel Cells: The Synergistic Effect of Pt and Ni

“…Second, different species of catalysts generate distinct battery performance . Because of their high reactivity, noble metals give rise to outstanding Li–O 2 battery performance, including the Pt, Pd, Au, and Ir. , As an additional bonus, their ability to suppress the formation of Li 2 CO 3 impurities can effectively extend the lifespan of Li–O 2 batteries. − However, the high cost of noble metals still limits its application and alternatively boosts the interest of cost-effective alternatives for Li–O 2 batteries. In this regard, transition metal oxides have an unfilled 4d orbit and exhibit high reactivity as an electron donor and therefore can act as high catalytic candidates for Li–O 2 batteries.…”

An Overview of Engineered Graphene‐Based Cathodes: Boosting Oxygen Reduction and Evolution Reactions in Lithium– and Sodium–Oxygen Batteries

“…[41] Ye et al reported the preparation of alloyedP tPd NPs anchored on the surfaceo fg raphene. [42] The poisoning resistanceo fp alladium, combinedw ith the high electroactivity of platinum, resultedi n an enhanced electrochemical performance. An adequate ratio of Pt to Pd was stablished to be Pt 60 Pd 40 ,w hich resulted in a lower first cycle overpotential and the best cyclability (80 cycles at 200 mA g À1 to 1000 mAh g À1 )among different alloying ratios.…”

“…Ye et al. reported the preparation of alloyed PtPd NPs anchored on the surface of graphene [42] . The poisoning resistance of palladium, combined with the high electroactivity of platinum, resulted in an enhanced electrochemical performance.…”