Size dependent oxygen reduction and methanol oxidation reactions: catalytic activities of PtCu octahedral nanocrystals

Abstract

The synthetic control through colloidal synthesis led to a remarkable increase in platinum mass activity in octahedral nanocrystals with Pt-rich surface. In this manuscript, we demonstrate that the ratio of...

Size and Composition Dependence of Oxygen Reduction Reaction Catalytic Activities of Mo-Doped PtNi/C Octahedral Nanocrystals

“…There is consensus that larger and compositionally uniform PtNi octahedral catalysts are needed to overcome the cost and degradation issues. − The most widely applied synthetic protocols for oh-PtNi NPs involve the reduction of Pt­(acac) 2 and Ni­(acac) 2 using dimethylformamide (DMF) as the solvent and reducing agent. The synthesis has been typically carried out in a sealed vessel (autoclaves, pressure flasks or vials), and the reaction temperature has been generally above the boiling points of both the DMF (153 °C) and the acetylacetonate ligand (140 °C). − The low Ni-content of the resulting NP catalysts (to a large degree Pt 3 Ni octahedra), combined with the weak reductive power of DMF raised doubts about the rate of reduction of Ni­(acac) 2 from Ni II to Ni 0 under these conditions. , Alternatively, Pt-rich oh-PtNi NPs have been synthesized at temperatures above 200 °C using oleylamine and oleic acid as solvents and capping agents and with or without tungsten hexacarbonyl as the reducing and shape-directing agent. − Wu et al proposed the use of benzyl alcohol (BA) as both solvent and reducing agent to produce larger bimetallic oh-PtNi NP catalysts (11.8 ± 1.2 nm apex to opposite apex).…”

On the electrocatalytical oxygen reduction reaction activity and stability of quaternary RhMo-doped PtNi/C octahedral nanocrystals

“…10 Inspired by the exceptional ORR activity reported on an extended Pt skin (111) surface, as well as advances in the synthesis of shaped NPs, numerous studies have investigated methods to prepare octahedral (oh-)Pt 3 Ni NPs with well-dened (111) facets for the ORR. 11,12 For example, Zou and Yang groups 13,14 produced oh-Pt 3 Ni NPs based on surfactant directed reduction in organic solution using tungsten carbonyl or CO (g) as the shaping agent. These particles showed a fourfold increase in specic activity (SA) compared to pure Pt/C electrocatalysts.…”

“…10 Inspired by the exceptional ORR activity reported on an extended Pt skin (111) surface, as well as advances in the synthesis of shaped NPs, numerous studies have investigated methods to prepare octahedral (oh-)Pt 3 Ni NPs with well-defined (111) facets for the ORR. 11,12…”

Ultrafine Rh nanocrystals immobilized on 3D boron and nitrogen co-doped graphene–carbon nanotube networks: high-efficiency electrocatalysts towards the methanol oxidation reaction

“…11,12 Over the past few decades, a great deal of research work has shown that platinum (Pt) and Pt-based catalysts have unique electrocatalytic properties for the MOR. [13][14][15] However, metallic Pt is not only very expensive as a scarce resource, but also easily poisoned by intermediate CO molecules generated during the MOR process, both of which severely impede the large-scale use of Pt catalysts. 16,17 These inherent weaknesses of Pt-based catalysts motivate researchers to explore a variety of non-Pt catalysts with acceptable costs.…”