A General Strategy to Remove Metal Aggregates toward Metal–Nitrogen–Carbon Catalysts with Exclusive Atomic Dispersion

Abstract

precious-metal-based ones. We envision that the generality of the NH 4 I-based method is not only limited to carbon-based SACs, but can also be extended to other types of supports. With the Pt-N-C HER catalyst as the example, we also demonstrated that the complete removal of the metal aggregates enabled the elucidation on the roles of the atomic PtN x sites and Pt NPs in contributing to the catalytic activity. Our strategy could be employed to assist the preparation of SACs with well-defined active sites and benefit the rational design of high-performance SACs.

Monometallic Ultrasmall Nanocatalysts via Different Valence Atomic Interfaces Boost Hydrogen Evolution Catalysis

“…The position of the Pt–Pt bonds in Pt/CNT and Pt foil is consistent. However, the Pt–Pt bond in N 2.42 -Pt/CNT is slightly more positive than Pt/CNT, suggesting the volume expansion of N 2.42 -Pt/CNT particles relative to Pt/CNT . Quantitative structure information can be obtained by least-squares EXAFS curve-fitting analysis, and the results showed the number of Pt–N and Pt–Pt coordination sites in N 2.42 -Pt/CNT (Figure S6 and Table S2, Supporting Information).…”

“…However, the Pt−Pt bond in N 2.42 -Pt/CNT is slightly more positive than Pt/CNT, suggesting the volume expansion of N 2.42 -Pt/CNT particles relative to Pt/CNT. 33 Quantitative structure information can be obtained by leastsquares EXAFS curve-fitting analysis, and the results showed the number of Pt−N and Pt−Pt coordination sites in N 2.42 -Pt/ CNT (Figure S6 and Table S2, Supporting Information). X-ray photoelectron spectroscopy (XPS) helps us to understand the valence electron structure of the catalysts.…”

Platinum Electrocatalyst Promoting Redox Kinetics of Li2S and Regulating Li2S Nucleation for Lithium–Sulfur Batteries

“…The high‐resolution TEM (HRTEM) image (Figure 2f) clearly demonstrates the presence of Pt nanoparticles and displays a lattice fringe spacing of 0.23 nm, corresponding to Pt (111) facets. [ 18 ] According to the statistical particle size distribution in Figure 2g, the size of Pt nanoparticles is in the range of 1.0–3.0 nm. This small particle size and narrow size distribution are advantageous for exposing more Pt active sites, thus accelerating the conversion of LiPSs.…”

Low-cost transition metal–nitrogen–carbon electrocatalysts for the oxygen reduction reaction: operating conditions from aqueous electrolytes to fuel cells

“…[61][62][63] Consequently, the heterogeneous composition of M-N-C catalysts makes the role of different components unclear. 64 Although it is generally believed that M-N x is the main active site, M-NPs have poor ORR activity and only catalyse the formation of graphite carbon and N-functional groups. 65,66 However, some researchers have pointed out that M-NPs are active components or enhance the activity of the M-N x site through synergistic effects.…”