IrPt Alloy Nanoparticles with Controllable Compositions as Catalysts for Electrochemical Oxygen and Hydrogen Evolution

Abstract

When two metal precursors are reduced to form alloy nanoparticles (NPs), the final size usually varies by the composition because the reduction rate is different for each precursor. In this study, we report that the composition of IrPt alloy NPs can be easily controlled without affecting the size using an antisolvent crystallization-based method owing to the separation of the particle growth and precursor reduction steps. The synthesized IrPt alloy NPs displayed low overpotentials in both hydrogen evolution reaction (65 mV with a Tafel slope of 32.2 mV dec −1 ) and oxygen evolution reaction (240 mV with a Tafel slope of 77.9 mV dec −1 ) to deliver a current density of 10 mA cm −2 in H 2 SO 4 (0.5 M), showing their enhanced electrocatalytic activities compared with the pure Pt and Ir catalysts.

Facile synthesis of AuIr alloy nanoparticles and their enhanced oxygen evolution reaction performance under acidic and alkaline conditions

“…This is because the formation process of the NPs was distinct from the reduction process of the precursors. 19 Here, it was possible to obtain Au 2 Ir alloy NPs with a high Au/Ir molar ratio while maintaining similar particle sizes of 2.11 nm just by modulating the molar ratio of Au and Ir precursors (Fig. 3(c) and S3(b) †).…”

“…We previously reported an antisolvent crystallization-based synthesis of AuCu and IrPt alloy NPs with controlled compositions. 18,19 In typical coreduction methods, alloy NPs are formed through the nucleation of monomers created by reducing precursors. The size of the NPs could vary with the different reduction rates of each precursor when the composition of the alloy NPs is controlled.…”

Bifunctional Pt–Ir nanoparticle catalysts for oxygen reduction and evolution reactions: investigating the influence of surface composition on the catalytic properties

“…13 The most suitable element for ORR is platinum, whereas the best one for OER catalysis in terms of activity and stability is Ir and its oxides. [14][15][16][17][18][19] In this context, the combination of the two elements, Pt and Ir, appears to be the simplest approach for developing a bifunctional oxygen catalyst (BOC). Initially, mechanical mixing of Pt and Ir nanopowders was a common route for BOC fabrication.…”

Amorphous/Crystalline Nanostructured WP/CoP-FeP4/NF Heterojunctions for Efficient Electrocatalytic Overall Water Splitting

“…10,11 Precious-metal catalysts exhibit excellent catalytic properties. 12,13 However, their prohibitive cost renders them unsuitable for large-scale commercial hydrogen production from electrochemical water splitting. Nonprecious metals present an exciting prospect as superior alternatives to precious metal catalysts due to their lower cost and potential catalytic activity.…”

“…Precious-metal catalysts exhibit excellent catalytic properties. , However, their prohibitive cost renders them unsuitable for large-scale commercial hydrogen production from electrochemical water splitting. Nonprecious metals present an exciting prospect as superior alternatives to precious metal catalysts due to their lower cost and potential catalytic activity. , Transition metal-based electrocatalysts possess abundant unpaired d-orbital electrons, which endow them with highly desirable catalytic potential and make them excellent catalysts for the electrochemical process of water splitting to produce hydrogen. , The catalytic performance of transition metal-based catalysts can be enhanced in various ways to approach or even surpass that of precious metal catalysts. , Consequently, low-cost alternatives can replace precious metal catalysts across all aspects, enabling large-scale production of hydrogen from electrolytic water.…”