Ultrafine and Ligand‐Free Precious Metal (Ru, Ag, Au, Rh and Pd) Nanoclusters Supported on Phosphorus‐Doped Carbon

Abstract

We report the use of phosphorus-doped carbon (P-C) as support to grow ultrasmall (1-3 nm) and ligand-free precious metal nanocrystals (PMNCs) via chemical reduction. We show that the valence states of surface phosphorus species are critical in tuning the affinity between the carbon support and metal precursors, which rationally controls the loading size and uniformity of resultant PMNCs. Five kinds of PMNCs, including Ru, Ag, Au, Rh, and Pd, were grown in situ to demonstrate the key role of surface phosphorus sites on the P-C support. As a proof-of-concept application, Ru nanocatalysts with an average diameter of 1.0±0.2 nm supported on P-C were examined for the electrocatalytic hydrogen evolution reaction (HER). Ultrasmall and ligand-free Ru nanocatalysts exhibited superior HER activity and stability compared to its counterparts with surface agents or larger sizes. An overpotential of 27.6 mV (vs. reversible hydrogen electrode) for Ru nanocatalysts was achieved at a current density of 10 mA cm . This novel method opens a new avenue to immobilize ligand-free and well-dispersed PMNCs on carbon; and, more importantly, it provides a new library of supported PMNCs with high catalytic activity.

Multimetallic Hollow Mesoporous Nanospheres with Synergistically Structural and Compositional Effects for Highly Efficient Ethanol Electrooxidation

“…Ag + is easier to be reduced into nanocrystals due to the higher reduction potential of Ag + /Ag, compared to Pd 2+ /Pd and Cu 2+ /Cu. 46 , 47 Our experimental observations implied that the quicker nucleation rate kinetically accelerated the growth of Pd-based nanocrystals into HMSs along vesicle and rod “dual”-template micelles simultaneously. By contrast, in the slower nucleation rate, thermodynamically stable rod micelles suppressed the vesicle one and resulted in the formation of solid MSs.…”

Advanced Carbon‐Based Nanocatalysts and their Application in Catalytic Conversion of Renewable Platform Molecules

“…Metal‐P species [70,72] Regulate acid site [50] Improve metal dispersion and stability [57,61,72,75] Regulate the affinity between carbon matrix and metal precursors [61] Regulate electronic structure of metal [71] Regulate the adsorption/desorption strength of substrate/intermediate [60,76] …”

“…Owing to larger atom radius and lower electronegativity than N atom, the doping of P into the carbon skeleton was greatly hindered [70] . With unceasing attempts, phosphorus‐doped carbon‐supported metal catalysts have made some progress in catalysis [57,60,61,70–76] . The role of P can be divided into two aspects: forming new active species with metals (such as metal‐P species) [70–72] or playing an auxiliary role to adjust the physical and chemical properties of metals, such as increasing the dispersion and stability of metals, [57,61,72,75] adjusting the electronic state of metals, [71] or improving the acidity of carbon matrix [50] .…”

Gold nanocatalysts supported on carbon for electrocatalytic oxidation of organic molecules including guanines in DNA

“…This may lead to the leaching of metal NPs in the catalytic process, resulting in the loss of catalytic performance. According to previous studies, through doping electron-rich heteroatoms like N, 95, 96 P, 97, 98 and S 99 elements into carbon nanomaterials, the electronic characteristics can be altered, thus producing more active sites and unexpected electrical and catalytic properties, such as high stability. 100 Zhang et al .…”