DNA‐Directed Growth of Pd Nanocrystals on Carbon Nanotubes towards Efficient Oxygen Reduction Reactions

Abstract

Unique DNA-promoted Pd nanocrystals on carbon nanotubes (Pd/DNA-CNTs) are synthesized for the first time, in which through its regularly arranged PO(4)(3-) groups on the sugar-phosphate backbone, DNA directs the growth of ultrasmall Pd nanocrytals with an average size of 3.4 nm uniformly distributed on CNTs. The Pd/DNA-CNT catalyst shows much more efficient electrocatalytic activity towards oxygen reduction reaction (ORR) with a much more positive onset potential, higher catalytic current density and better stability than other Pd-based catalysts including Pd nanocrystals on carbon nanotubes (Pd/CNTs) without the use of DNA and commercial Pd/C catalyst. In addition, the Pd/DNA-CNTs catalyst provides high methanol tolerance. The high electrocatalytic performance is mainly contributed by the ultrasmall Pd nanocrystal particles grown directed by DNA to enhance the mass transport rate and to improve the utilization of the Pd catalyst. This work may demonstrate a universal approach to fabricate other superior metal nanocrystal catalysts with DNA promotion for broad applications in energy systems and sensing devices.

Formic acid-reduced ultrasmall Pd nanocrystals on graphene to provide superior electocatalytic activity and stability toward formic acid oxidation

“…The calculated ECSA of Pd@Graphene and commercial Pd/C is 56.0 m 2 g À 1 and 31.7 m 2 g À 1 , respectively. In addition, the hydrogen adsorption/desorption peaks on the Pd@Graphene is significantly larger than that of the commercial one, further conforming the larger ECSA [1,29]. The remarkable results might be ascribed to the smaller Pd nanocrystals of Pd@Gra-phene.…”

Ultrasonic-assisted synthesis of Pd–Pt/carbon nanotubes nanocomposites for enhanced electro-oxidation of ethanol and methanol in alkaline medium

“…Meantime, all the patterns clearly showed other three main characteristic peaks of face-centered cubic crystalline within 30-80°. For Pd/CNTs and Pt/CNTs, three peaks were observed, which matched well with those of Pd (01-1201) [37] and Pt (04-0802) [38] respectively in the Joint Committee Powder Diffraction Standard. It was noteworthy that the 2h values of the (1 1 1) lattice plane [39] for the Pd 3 Pt/CNTs, PdPt/CNTs and [40].…”

One-pot synthesis of small and uniform Au@PtCu core–alloy shell nanoparticles as an efficient electrocatalyst for direct methanol fuel cells

“…(1). [33,34] ECSA = Q 0.21m Ccm −2 × Pt m (1) where Q (mC) and Pt m are the charge calculated from hydrogen adsorption/desorption region and the integrated Pt loaded on the electrode surface, respectively. 0.21mC cm −2 is the charge assuming monolayer adsorption of hydrogen occurs on Pt.…”