Single atomic metal–N–C materials have attracted immense interest as promising candidates to replace noble metal‐based electrocatalysts for the oxygen reduction reaction (ORR). The coordination environment of metal–N–C active centers plays a critical role in determining their catalytic activity and durability, however, attention is focused only on the coordination of metal atoms. Herein, Fe single atoms and clusters co‐embedded in N‐doped carbon (Fe/NC) that deliver the synergistic enhancement in pH‐universal ORR catalysis via the four‐electron pathway are reported. Combining a series of experimental and computational analyses, the geometric and electronic structures of catalytic sites in Fe/NC are revealed and the neighboring Fe clusters are shown to weaken the binding energies of the ORR intermediates on Fe–N sites, hence enhancing both catalytic kinetics and thermodynamics. This strategy provides new insights into the understanding of the mechanism of single atom catalysis.

The catalytic oxidation of toluene has been investigated using a series of Pt/SBA-15 and Pt/SiO 2 catalysts, and the Pt/SBA-15 catalyst exhibits significantly higher catalytic activity for the oxidation of toluene than the Pt/SiO 2 catalysts. The SBA-15-supported Pt nanoparticles possess the ability to strongly dissociate toluene to benzene, hydrocarbon fragments (CH x ), and H 2 at low temperatures, but the Pt/SiO 2 catalysts are nonreactive toward the decomposition of toluene. The products resulting from the dissociation of toluene were easily oxidized by oxygen, thereby positively affecting the conversion rate of toluene oxidation on Pt/ SBA-15. Temperature-programmed desorption measurements clearly indicate that the dissociation reaction mainly consists of breakage of the C−C bonds between the phenyl and methyl groups. Combined density functional theory (DFT) calculations and DRIFT spectroscopy are carried out to investigate the stretching frequency of CO adsorbed on the defect sites of various Pt clusters, suggesting that the subnanosized Pt particles (icosahedron cluster) and/or Pt single atom may be formed in the structure of SBA-15. Pt sites associated with low coordination and subnanoscale Pt particles and/or single Pt atoms in the SBA-15 support can facilitate toluene adsorption and induce strong dissociation.

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SrTiO3 is a well‐known photocatalyst inducing overall water splitting when exposed to UV irradiation of wavelengths <370 nm. However, the apparent quantum efficiency of SrTiO3 is typically low, even when functionalized with nanoparticles of Pt or Ni@NiO. Here, we introduce a simple solid‐state preparation method to control the incorporation of magnesium into the perovskite structure of SrTiO3. After deposition of Pt or Ni@NiO, the photocatalytic water‐splitting efficiency of the Mg:SrTiOx composites is up to 20 times higher compared to SrTiO3 containing similar catalytic nanoparticles, and an apparent quantum yield (AQY) of 10 % can be obtained in the wavelength range of 300–400 nm. Detailed characterization of the Mg:SrTiOx composites revealed that Mg is likely substituting the tetravalent Ti ion, leading to a favorable surface–space–charge layer. This originates from tuning of the donor density in the cubic SrTiO3 structure by Mg incorporation and enables high oxygen‐evolution rates. Nevertheless, interfacing with an appropriate hydrogen evolution catalyst is mandatory and non‐trivial to obtain high‐performance in water splitting.