Ultrafine Core@Shell Cu₁Au₁@Cu₁Pd₃ Nanodots Synergized with 3D Porous N-Doped Graphene Nanosheets as a High-Performance Multifunctional Electrocatalyst

Abstract

Rationally combining designed supports and metal-based nanomaterials is effective to synergize their respective physicochemical and electrochemical properties for developing highly active and stable/durable electrocatalysts. Accordingly, in this work, sub-5 nm and monodispersed nanodots (NDs) with the special nanostructure of an ultrafine Cu1Au1 core and a 2–3-atomic-layer Cu1Pd3 shell are synthesized by a facile solvothermal method, which are further evenly and firmly anchored onto 3D porous N-doped graphene nanosheets (NGS) via a simple annealing (A) process. The as-obtained Cu1Au1@Cu1Pd3 NDs/NGS-A exhibits exceptional electrocatalytic activity and noble-metal utilization toward the alkaline oxygen reduction, methanol oxidation, and ethanol oxidation reactions, showing dozens-fold enhancements compared with commercial Pd/C and Pt/C. Besides, it also has excellent long-term electrochemical stability and electrocatalytic durability. Advanced and comprehensive experimental and theoretical analyses unveil the synthetic mechanism of the special core@shell nanostructure and further reveal the origins of the significantly enhanced electrocatalytic performance: (1) the prominent structural properties of NGS, (2) the ultrasmall and monodispersed size as well as the highly uniform morphology of the NDs-A, (3) the special Cu–Au–Pd alloy nanostructure with an ultrafine core and a subnanometer shell, and (4) the strong metal–support interaction. This work not only develops a facile method for fabricating the special metal-based ultrafine-core@ultrathin-shell nanostructure but also proposes an effective and practical design paradigm of comprehensively and rationally considering both supports and metal-based nanomaterials for realizing high-performance multifunctional electrocatalysts, which can be further expanded to other supports and metal-based nanomaterials for other energy-conversion or environmental (electro)catalytic applications.

Monodisperse Sea-Urchin-like Nanodendrites and Nanoparticles of Multicomponent Pd-Based Alloys for Enhanced C2 Alcohol Oxidation Activity

“…The corresponding terrace-step notation for a Pd ( n + 1, n + 1, n - 1) surface is Pd ( S ) - [ n (1 1 1) × (1 1 0)], where n represents the width in the number of the (1 1 1) terrace atoms (Figure i). For example, Pd (3 3 1) and Pd (2 2 1) surfaces can be expressed as Pd ( S ) - [2 (1 1 1) × (1 1 0)] and Pd ( S ) - [3 (1 1 1) × (1 1 0)], respectively, indicating a stepped surface composed of a terrace of two and five atomic widths of (1 1 1) symmetry. , …”

Nitrogen-doped carbon nanotubes embedded with nitrogen-doped carbon black anchoring Pd nanocrystals to boost ethanol electrooxidation

“…35 The strong interaction between Pd and nitrogen-containing functional groups regulates the electronic structure of Pd and impedes the detachment of Pd during the EOR process, thereby improving the electrocatalytic activity and strengthening the long-term stability. 36 Besides, N atoms with larger electron affinity can provide abundant OH sources to oxidize the fragments of oxidation of small alcohols based on the literature, contributing to improved catalytic activity and enhanced long-term durability. 37 Second, the prominent three-dimensional network structural properties of NCB@NCNTs can enable a hierarchical porous structure with diverse micro-, meso- and macro-pores, which significantly accelerates the mass-transfer rate during the EOR.…”

Phosphorus-Doped PdSn Nanowires for Electrocatalytic Alcohol Oxidation

“…Direct alcohol fuel cells have become a kind of clean energy power source that is very promising because of its advantages of easy access to raw materials, convenient storage and transportation, and environmental friendliness. − For the fuel cell, the core component that determines the output power and life is the catalyst. − At present, palladium-based catalysts show good catalytic properties in alkaline direct alcohol fuel cells due to their good oxygen affinity. − However, when considering practical applications, their catalytic activity and stability are still low. , The activity and stability of a nanocatalyst are closely related to its nanostructure. − Therefore, it is urgent to design the nanostructure of palladium-based nanocatalysts reasonably and to synthesize highly efficient palladium-based nanocatalysts in order to promote their catalytic efficiency in direct alcohol fuel cells.…”