title: High-yield synthesis of sub-10 nm Pt nanotetrahedra with bare ⟨111⟩ facets for efficient electrocatalytic applications.
abstract: Unlike other shapes, the design of tetrahedral Pt nanocrystals (Pt-NTd), which have the largest number of Pt(111) surface atoms and highest catalytic activities toward the electron transfer reactions, has widely been considered a synthetic challenge due to their thermodynamic instability. Here, we show that, by inducing their nucleation on functionalized carbon, Pt NTds can be obtained with tunable sizes and high yields. The carbon support anchors the nanocrystals early and prevents their oriented attachment leading to nanowire formation. Therein, an in situ generated amine is crucial for stabilization of Pt-NTds, which can later be removed to expose the Pt(111) facets for higher catalytic efficiency. The bare nanocrystals exhibit much improved stability and electrocatalytic activity characteristic of Pt(111) toward oxygen reduction reaction (ORR) and methanol and formic acid oxidation reactions. For example, ∼90% of their activity was retained after 5000 potential cycles, while the ORR onset potential was recorded to be very high, 1.01 V vs reversible hydrogen electrode (RHE).
authors: New Chemistry Unit, ∥International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research , Bangalore 560064, India.
authors: Moumita
authors: M
authors: Rana
authors: Manjeet
authors: M
authors: Chhetri
authors: B
authors: B
authors: Loukya
authors: Pramod K
authors: PK
authors: Patil
authors: Ranjan
authors: R
authors: Datta
authors: Ujjal K
authors: UK
authors: Gautam
keywords: Pt(111); electrocatalysis; fuel cell; metal nanocrystals; methanol oxidation; oxygen reduction reaction