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Carbon-supported nanoparticles are indispensable to enabling new energy technologies such as metal-air batteries and catalytic water splitting. However, achieving ultrasmall and high-density nanoparticles (optimal catalysts) faces fundamental challenges of their strong tendency toward coarsening and agglomeration. Herein, we report a general and efficient synthesis of high-density and ultrasmall nanoparticles uniformly dispersed on two-dimensional porous carbon. This is achieved through direct carbothermal shock pyrolysis of metal-ligand precursors in just ~100 ms, the fastest among reported syntheses. Our results show that the in situ metal-ligand coordination (e.g., N → Co2+) and local ordering during millisecond-scale pyrolysis play a crucial role in kinetically dominated fabrication and stabilization of high-density nanoparticles on two-dimensional porous carbon films. The as-obtained samples exhibit excellent activity and stability as bifunctional catalysts in oxygen redox reactions. Considering the huge flexibility in coordinated precursors design, diversified single and multielement nanoparticles (M = Fe, Co, Ni, Cu, Cr, Mn, Ag, etc) were generally fabricated, even in systems well beyond traditional crystalline coordination chemistry. Our method allows for the transient and general synthesis of well-dispersed nanoparticles with great simplicity and versatility for various application schemes. Well-dispersed nanoparticles are critical for catalysis but face challenges of easy agglomeration. Here the authors report synthesis of ultrasmall nanoparticles anchored on two-dimensional porous carbon via coordinated carbothermal shock and the application of resulted nanoparticles as catalysts for oxygen electrocatalysis. [ABSTRACT FROM AUTHOR]

The biomass‐derived alcohol oxidation reaction (BDAOR) holds great promise for sustainable production of chemicals. However, selective electrooxidation of alcohols to value‐added aldehyde compounds is still challenging. Herein, we report the electrocatalytic BDAORs to selectively produce aldehydes using single‐atom ruthenium on nickel oxide (Ru1‐NiO) as a catalyst in the neutral medium. For electrooxidation of 5‐hydroxymethylfurfural (HMF), Ru1‐NiO exhibits a low potential of 1.283 V at 10 mA cm−2, and an optimal 2,5‐diformylfuran (DFF) selectivity of 90 %. Experimental studies reveal that the neutral electrolyte plays a critical role in achieving a high aldehyde selectivity, and the single‐atom Ru boosts HMF oxidation in the neutral medium by promoting water dissociation to afford OH*. Furthermore, Ru1‐NiO can be extended to selective electrooxidation of a series of biomass‐derived alcohols to corresponding aldehydes, which are conventionally difficult to obtain in the alkaline medium. [ABSTRACT FROM AUTHOR]