Atomic cerium modulated palladium nanoclusters exsolved ferrite catalysts for lean methane conversion

Atomically precise silver-based bimetallic clusters for electrocatalytic urea synthesis

Electrocatalytic urea synthesis from CO2 and nitrate holds immense promise as a sustainable strategy, but its complicated synthesis steps and controversial C-N coupling mechanism restrict the design of efficient catalysts. Atomically precise metal cluster materials are ideal model catalysts for investigating the C-N coupling issues. Here we synthesize two atomically precise bimetallic clusters, Ag14Pd(PTFE)6(TPP)8 and Ag13Au5(PTFE)10(DPPP)4, both with icosahedral cores and similar ligands. We demonstrate that both clusters have good performance for electrocatalytic urea synthesis, with the production rates at the maximum Faradaic efficiency of 143.3 and 82.3 mg h-1 gcat -1, respectively. Bimetallic structures can induce charge polarization at the active sites of metal clusters, thereby influencing the selectivity. In mechanistic investigations, we propose that *NOH and *COOH are the rate-limiting steps for the reduction of nitrate and CO2, respectively, and that the key intermediates formed thereafter can significantly affect the C-N coupling process. This approach offers a deep understanding into C-N coupling through the utilization of atomically precise metal clusters.

Unlocking High-Efficiency Methane Oxidation with Bimetallic Pd-Ce Catalysts under Zeolite Confinement

Catalytic complete oxidation is an efficient approach to reducing methane emissions, a significant contributor to global warming. This approach requires active catalysts that are highly resistant to sintering and water vapor. In this work, we demonstrate that Pd nanoparticles confined within silicalite-1 zeolites (Pd@S-1), fabricated using a facile in situ encapsulation strategy, are highly active and stable in catalyzing methane oxidation and are superior to those supported on the S-1 surface due to a confinement effect. The activity of the confined Pd catalysts was further improved by co-confining a suitable amount of Ce within the S-1 zeolite (PdCe_0.4@S-1), which is attributed to confinement-reinforced Pd-Ce interactions that promote the formation of oxygen vacancies and highly reactive oxygen species. Furthermore, the introduction of Ce improves the hydrophobicity of the S-1 zeolite and, by forming Pd-Ce mixed oxides, inhibits the transformation of the active PdO phase to inactive Pd(OH)₂ species. Overall, the bimetallic PdCe_0.4@S-1 catalyst delivers exceptional outstanding activity and durability in complete methane oxidation, even in the presence of water vapor. This study may provide new prospects for the rational design of high-performance and durable Pd catalysts for complete methane oxidation.

Clusterbody Enables Flow Sorting-Assisted Single-Cell Mass Spectrometry Analysis for Identifying Reversal Agent of Chemoresistance

Identifying effective reversal agents overcoming multidrug resistance with causal mechanisms from an efflux pump protein is of vital importance for enhanced tumor chemotherapy in clinic. To achieve this end, we construct a metal cluster-based probe, named clusterbody, to develop flow sorting-assisted single-cell mass spectrometry analysis. This clusterbody synthesized by biomimetic mineralization possesses an antibody-like property to selectively recognize an efflux pump protein. The intrinsic red fluorescence emission of the clusterbody facilitates fluorescence-activated high-throughput cell sorting of subpopulations with different multidrug resistance levels. Furthermore, based on the accurate formula of the clusterbody, the corresponding protein abundance at the single-cell level is determined through detecting gold content via precise signal amplification by laser ablation inductively coupled plasma mass spectrometry. Therefore, the effect of reversal agent treatment overcoming multidrug resistance is evaluated in a quantitative manner. This work opens a new avenue to identify reversal agents, shedding light on developing combined or synergetic tumor therapy.