Fast and Facile Synthesis of Pt Nanoparticles Supported on Ketjen Black by Solution Plasma Sputtering as Bifunctional HER/ORR Catalysts

Abstract

Hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) are two core electrochemical processes involved in hydrogen fuel cell (HFC) technology. ORR is a cathodic reaction occurring in HFC, whereas HER can convert the H2O byproduct from HFCs into H2 gas via water splitting. Platinum (Pt)-based catalysts are the most effective catalysts for both reactions. In this work, we used a fast, facile, and chemical-free method, called solution plasma sputtering (SPS), to synthesize Pt nanoparticles supported on Ketjen Black (KB). The discharge time was varied (5, 10, and 20 min) to alter the Pt loading. Characterization results revealed that the plasma did not affect the morphology of KB, and the Pt loading on KB increased with increasing discharge time (5.5–17.9 wt%). Well-crystallized Pt nanoparticles, ~2–5 nm in diameter, were obtained. Electrochemical measurements revealed that Pt/KB exhibited bifunctional catalytic activity toward HER and ORR in 0.5 M H2SO4 solution. Both HER and ORR activities enhanced as the loading of Pt nanoparticles increased with a longer discharge time. Moreover, Pt/KB exhibited better HER and ORR stability than a commercial Pt-based catalyst, which was attributed to the stronger adhesion between Pt nanoparticles and KB support. Thus, SPS can be applied as an alternative synthesis method for preparing Pt/KB catalysts for HER and ORR.

Plasma Technology Applications in Proton Exchange Membrane Fuel Cell Systems

“…This research laid the foundation for the production of platinum-based catalysts using plasma (Figure 2b-d). Mani-Late et al [30] doped Pt nanoparticles onto carbon black (KB) through solution plasma sputtering, obtaining Pt/KB materials. As the discharge time increased from 5 minutes to 20 minutes, the loading of Pt nanoparticles increased from 5.5 wt.% to 17.9 wt.%.…”

“…This research laid the foundation for the production of platinum‐based catalysts using plasma (Figure 2b–d). Mani‐Late et al [30] . doped Pt nanoparticles onto carbon black (KB) through solution plasma sputtering, obtaining Pt/KB materials.…”

The Recent Progress of Oxygen Reduction Electrocatalysts Used at Fuel Cell Level

“…Besides, Chitlada et al obtained Pt NPs supported by Ketjen Black (KB) as the matrix through solution plasma sputtering (SPS) method, wherein the loading capacity of Pt NPs on KB could be easily controlled from 5.5% to 17.9 wt.% by adjusting the discharge time from 5 to 20 min. [33] This ingenious approach requires no chemical reducing agent so that the obtained NPs contain a clean surface without any organic layer hindering surficial active sites. The catalyst displayed an excellent ORR activity with an onset potential (E onset ) almost identical to the 20 wt.% Pt on Vulcan XC-72 (20% Pt/VC, 0.826 V), as well as more remarkable stability than 20 wt.% Pt/VC in 0.5 m H 2 SO 4 solution.…”

Submerged Discharges in Liquids for Nanoobject Synthesis: Expectations and Capabilities

“…Liu et al [46] have reported that the mass of Pt nanoparticles generated by erosion is mainly influenced by the diameter of the discharge electrodes and the discharge time, but no further details are given. Mani-Lata et al [47] observed an increase in the production of platinum nanoparticles with time in a solution containing Ketjen Black (KB) particles (30-50 nm in size), but the possible effect of the presence of KB was not described.…”

“…Controlling size distributions is a key factor in the properties of materials made of nanoobjects. For instance, it is relatively simple to produce platinum nanoparticles with diameters around or even below 5 nm [46,47,59,122]. In contrast, manganese oxide nanoparticles are generally larger (between 20 and 100 nm typically) [9,60,91,94].…”