Identifying active sites in heterogeneous catalysis has intrigued researches for many decades yet remains a challenge. This becomes more challenging to reveal the responsiveness of local sites on a catalyst to reactive species during a reaction. Here we utilize a flexible Au₁₀(DPPF)₄PPh₃ cluster to pinpoint active sites and untangle the communication between adjacent sites to match transient intermediates underlying the key steps from KA oil oxidation to ε-caprolactone. Our study suggests that the detachment of a triphenylphosphine ligand at the initial reaction exposes one Au atom and breaks one Au–Au bond on this cluster, thereby invoking two Au atoms to activate dioxygen and benzaldehyde to form benzoyl hydroperoxide intermediate. Sequentially, the two Au atoms spontaneously approach to adapt to the bridged adsorption of benzaldehyde over the two sites, leading to re-bonding of the two Au atoms and meanwhile stabling the cluster structure. More notably, the desorption of hydroperoxide intermediate from the active sites persuades this Au–Au bond to open again for being active sites in the next cycle. This interactive catalysis between active sites and reactants leads to benzoyl hydroperoxide affluently produced on the cluster to oxidize KA oil, eventually achieving a record-high synthesis efficiency for ε-caprolactone.

Metal nanoclusters (NCs) combine the advantages of organic molecules and inorganic nanomaterials, which are promising alternatives in optoelectronic applications. However, for efficient photoluminescence, excited-state compositions of cluster emitter should be tuned through ligand engineering to enhance ligand-centered radiative components and reduce cluster-centered quenching states, which requires delicate and controllable ligand functionalization. In this work, we develop an effective method to augment cluster photoluminescence, which can facilitate the enhancement of phosphorescence emission from several clusters within thin films by leveraging host–guest interactions. The transient absorption spectra and time-resolved emission spectra explicate that energy transfer occurs from the predominant host molecules to the guest clusters by absorption of supplementary photon energy and convering it via the Förster resonance energy transfer (FRET) mechanism. Our discovery paves the way for efficient light harvesting of NCs with simple fabrication using thin films.

As the sole renewable organic carbon source in nature, biomass holds irreplaceable strategic significance in sustainable energy systems. The catalytic conversion of biomass-derived ethanol into high-value multi-carbon chemicals not only provides a crucial alternative to fossil-based routes for producing bulk chemicals but also represents a key breakthrough toward achieving green chemistry and circular economies. In the realm of biomass-derived platform molecules, ethyl acetate (EA) occupies a pivotal role as an industrial solvent and a fundamental chemical compound. Its annual demand, estimated to be in the millions of tons, has garnered significant attention due to the pressing need for green synthesis technologies. Notably, the one-step catalytic synthesis of EA from bioethanol has emerged as a research hotspot in catalysis, owing to its unique advantages: renewable feedstock, clean production processes, exceptional atom economy, and the generation of high-purity hydrogen as a valuable byproduct. This review systematically introduces recent advancements in ethanol dehydrogenative coupling for EA production, with a focus on catalyst design strategies—including active site engineering and support engineering and their critical roles in regulating reaction pathways. By establishing comprehensive correlations among catalyst architecture, mechanistic pathways, and catalytic performance, we elucidate the merits and limitations of existing catalytic systems. Furthermore, the comprehensive analysis of structure-activity relationships in this work provides viable guidelines for the design of next-generation catalytic systems, which will ultimately advance the development of economically viable and sustainable ethanol valorization technologies.

The structure determination of metal nanoclusters protected by ligands is critical in understanding their physical and chemical properties, yet it remains elusive how the metal core and ligand of metal clusters cooperatively contribute to the observed performances. Here, with the successful synthesis of Au₄₄TBPA₂₂Cl₂ cluster (TBPA = 4-tert-butylphenylacetylene), the structural isomer of previously reported Au₄₄L₂₈ clusters (L denoted as ligand) is filled, thereby providing an opportunity to explore the property evolution rules imparted by different metal core structures or different surface ligands. Time-resolved transient absorption spectroscopy reveals that the difference in the core structure between Au₄₄TBPA₂₂Cl₂ and Au₄₄L₂₈ can bring nearly 360 times variation of excited-state lifetime, while only 3–24 times differences in excited-state lifetimes of the three Au₄₄L₂₈ nanoclusters with identical metal core but different ligands are observed, which is due to much stronger impact of the metal core than the surface ligands in the electronic energy bands of the clusters. In addition, the Au₄₄ clusters protected by alkyne ligands are shown to be highly effective toward the electrochemical oxidation of ethanol, compared to the Au₄₄ clusters capped by thiolates, which is ascribed to smaller charge transfer impedance of the former clusters. We anticipate that the study will enhance the process in controlling the nanomaterial properties by precisely tailoring metal core or surface patterns.

It remains elusive to realize the distinct catalysis of isomeric catalysts because it becomes challenging to identify structural isomers in the polydisperse nanoparticles. Herein we investigate catalysis of two geometric isomers for 36-gold-atom nanoclusters with different Au cores arrangements but the same thiolate ligands, thereby providing access to isomer catalysts readily participate in a desired reaction. Compared to the Au₃₆(SR)₂₄ with a one-dimensional (1D) layout of Au₄ tetrahedral units, the Au₃₆(SR)₂₄ with a two-dimensional (2D) layout of Au₄ tetrahedral units is more effective for the intramolecular hydroamination of alkyne. Our study suggests that the exposed Au sties of the two Au₃₆(SR)₂₄ catalysts favor different reaction intermediates and pathways. The intramolecular H transfer leads to intermediates with the C–N and with C=N for the 1D and 2D Au₃₆(SR)₂₄ respectively, and hence the different on-site and off-site pathways for the successive reaction steps account for the different performances of the two Au₃₆(SR)₂₄ catalysts.