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Hydrogenation reactions are industrially important reactions that typically require unfavorably high H2 pressure and temperature for many functional groups. Herein we reveal surprisingly strong size-dependent activity of Pt nanoparticles (PtNPs) in catalyzing this reaction. Based on unambiguous spectral analyses, the size effect has been rationalized by the size-dependent d-band electron structure of the PtNPs. This understanding enables production of a catalyst with size of 1.2 nm, which shows a sixfold increase in turnover frequency and 28-fold increase in mass activity in the regioselective hydrogenation of quinoline, compared with PtNPs of 5.3 nm, allowing the reaction to proceed under ambient conditions with unprecedentedly high reaction rates. The size effect and the synthesis strategy developed herein may provide a general methodology in the design of metal-nanoparticle-based catalysts for a broad range of organic syntheses.

Highlights: Developing surface-functionalized catalysts with exceptional activity and selectivity for the electrocatalytic CO2RR to C2+ products under neutral electrolyte. A remarkable C2+ FE of nearly 90% at an unprecedented current density of 300 mA cm−2 and maintain high FE (> 80%) at the wide current density performance (100–600 mA cm−2) in neutral environments using a flow cell as well as MEA electrolyzer. Mechanical study reveals that reducing the coverage of coordinated K·H2O water increased the probability of intermediate reactants (CO) interacting with the surface, thereby promoting efficient C–C coupling and enhancing the yield of C2+ products. Surface functionalization of Cu-based catalysts has demonstrated promising potential for enhancing the electrochemical CO2 reduction reaction (CO2RR) toward multi-carbon (C2+) products, primarily by suppressing the parasitic hydrogen evolution reaction and facilitating a localized CO2/CO concentration at the electrode. Building upon this approach, we developed surface-functionalized catalysts with exceptional activity and selectivity for electrocatalytic CO2RR to C2+ in a neutral electrolyte. Employing CuO nanoparticles coated with hexaethynylbenzene organic molecules (HEB-CuO NPs), a remarkable C2+ Faradaic efficiency of nearly 90% was achieved at an unprecedented current density of 300 mA cm−2, and a high FE (> 80%) was maintained at a wide range of current densities (100–600 mA cm−2) in neutral environments using a flow cell. Furthermore, in a membrane electrode assembly (MEA) electrolyzer, 86.14% FEC2+ was achieved at a partial current density of 387.6 mA cm−2 while maintaining continuous operation for over 50 h at a current density of 200 mA cm−2. In-situ spectroscopy studies and molecular dynamics simulations reveal that reducing the coverage of coordinated K⋅H2O water increased the probability of intermediate reactants (CO) interacting with the surface, thereby promoting efficient C–C coupling and enhancing the yield of C2+ products. This advancement offers significant potential for optimizing local micro-environments for sustainable and highly efficient C2+ production. [ABSTRACT FROM AUTHOR]

Atomically precise ~1‐nm Pt nanoparticles (nanoclusters, NCs) with ambient stability are important in fundamental research and exhibit diverse practical applications (catalysis, biomedicine, etc.). However, synthesizing such materials is challenging. Herein, by employing the mixture ligand protecting strategy, we successfully synthesized the largest organic‐ligand‐protected (~1‐nm) Pt23 NCs precisely characterized with mass spectrometry and single‐crystal X‐ray diffraction analyses. Interestingly, natural population analysis and Bader charge calculation indicate an alternate, varying charge ‐layer distribution in the sandwich‐like Pt23 NC kernel. Pt23 NCs can catalyze the oxygen reduction reaction under acidic conditions without requiring calcination and other treatments, and the resulting specific and mass activities without further treatment are sevenfold and eightfold higher than those observed for commercial Pt/C catalysts, respectively. Density functional theory and d‐band center calculations interpret the high activity. Furthermore, Pt23 NCs exhibit a photothermal conversion efficiency of 68.4 % under 532‐nm laser irradiation and can be used at least for six cycles, thus demonstrating great potential for practical applications. [ABSTRACT FROM AUTHOR]

Herein, a facile seed‐assisted strategy for preparing Cu nanoparticles (NPs) with polyvinyl pyrrolidone (PVP) capping is presented. Compared to the Cu NPs with deficient PVP protection, the Cu NPs capped with a sufficient amount of PVP remain almost completely as Cu0 species. In contrast, the Cu NPs that are considered PVP deficient form an oxide structure in which the inner layer is face‐centered cubic Cu and the outer layer is, at least in part, made up of Cu2O species. Furthermore, to eliminate CO2 molecule diffusion and simultaneously obtain significant current density (200 mA cm−2) for industrial applications, a flow cell configuration is used for carbon dioxide electro reduction reaction (CO2RR) testing in 0.5 m potassium hydroxide solution. The Cu NPs with zero valence deliver Faradaic efficiencies (FEs) for the CO2 reduction to CH4 of over 70%, with a current density exceeding 200 mA cm−2, outstripping the performances of the majority of the reported CO2 electrocatalysts. Interestingly, the distribution of products catalyzed by the Cu NPs with +1 valence includes multicarbon products (C2+) such as C2H4, C2H5OH, CH3COOH, and C3H7OH with combined FEs of >80%, with current densities of up to 300 mA cm−2. The above results unambiguously establish that surface oxidation of Cu species plays a crucial role in the CO2RR. [ABSTRACT FROM AUTHOR]

This article, published in Angewandte Chemie, discusses the discovery of the largest organic-ligand-protected Pt nanoclusters with atomic precision. The researchers found that these Pt23 nanoclusters exhibited superior catalytic activity for the oxygen reduction reaction under acidic conditions compared to commercial Pt/C catalysts, without the need for additional treatments. Additionally, the nanoclusters demonstrated excellent photothermal conversion efficiency, suggesting potential applications in various fields. The article also briefly mentions other research topics, including the synthesis of sulfur-containing polymers and the development of naphthalene diimide anolytes for neutral flow batteries. [Extracted from the article]

Abstract: A novel disintegration–reassembly route is reported for the synthesis of mesoporous TiO2 nanocrystalline hollow spheres with controlled crystallinity and enhanced photocatalytic activity. In this unique synthesis strategy, it is demonstrated that sol–gel‐derived mesoporous TiO2 colloidal spheres can be disintegrated into discrete small nanoparticles that are uniformly embedded in the polymer (polystyrene, PS) matrix by surface‐induced photocatalytic polymerization. Subsequent reassembly of these TiO2 nanoparticles can be induced by an annealing process after further coating of a resorcinol–formaldehyde (RF) resin, which forms self‐supported hollow spheres of TiO2 at the PS/RF interface. The abundant phenolic groups on the RF resin serve as anchoring sites for the TiO2 nanoparticles, thus enable the reassembly of the TiO2 nanoparticles and prevent their sintering during the thermal crystallization process. This unique disintegration–reassembly process leads to the formation of self‐supported TiO2 hollow spheres with relatively large surface area, high crystallinity, and superior photocatalytic activity in dye degradation under UV light irradiation. [ABSTRACT FROM AUTHOR]

Manipulating Cu Nanoparticle Surface Oxidation States Tunes Catalytic Selectivity toward CH4 or C2+ Products in CO2 Electroreduction (Adv. CO 2 electroreduction, Cu nanoparticles, Cu oxidation Keywords: CO 2 electroreduction; Cu nanoparticles; Cu oxidation EN CO 2 electroreduction Cu nanoparticles Cu oxidation 1 1 1 09/27/21 20210923 NES 210923 B CO SB 2 sb Electroreduction b In article number 2101424, Xuezhi Duan, Jin Wang, Jian Yang and co-workers report an effective strategy to manipulate Cu surface oxidation states by polyvinyl pyrrolidone coverage on the surface of Cu nanoparticles. [Extracted from the article]

The effectuation of the Zn-air battery (ZAB) is appealing for active and durable catalysts to kinetically drive the sluggish cathodic oxygen reduction reaction (ORR). Atomic metal-N x -C sites are widely witnessed with Pt-like activity, but their demetalations still severely restrict the durability in ORR. Here we have profiled an ordered hierarchical porous carbon supported Fe-N 4 single-atom (FeNC) catalyst by a template derivation method for efficient ORR and flexible ZAB studies. The FeNC structure is observed with a sub-polarized graphitic Fe-N 4 coordination with a shortened Fe-N bond for potentially consolidating the ORR, together with the hierarchical porous matrix for kinetical mass transfer. Resultantly, the optimized FeNC catalyst showcases Pt-beyond alkaline ORR activity ( E 1/2 = 0.95 V) with long-term durability for 100 h, delivering the flexible ZAB device with high power density (251 mW cm -2 ) and durable cycle life (80 h). This research underscores the criterion in rationalizing active and robust ORR catalysts through metal-nitrogen bond modulation.

Structural engineering of nanomaterials offers a promising way for developing high-performance catalysts toward catalysis. However, the delicate modulation of thermodynamically unfavorable nanostructures with unconventional phases still remains a challenge. Here, the synthesis of hierarchical AuCu nanostructures is reported with hexagonal close-packed (2H-type)/face-centered cubic (fcc) heterophase, high-index facets, planar defects (e.g., stacking faults, twin boundaries, and grain boundaries), and tunable Cu content. The obtained 2H/fcc Au 99 Cu 1 hierarchical nanosheets exhibit excellent performance for the electrocatalytic CO 2 reduction to produce CO, outperforming the 2H/fcc Au 91 Cu 9 and fcc Au 99 Cu 1 . The experimental results, especially those obtained by in-situ differential electrochemical mass spectroscopy and attenuated total reflection Fourier-transform infrared spectroscopy, suggest that the enhanced catalytic performance of 2H/fcc Au 99 Cu 1 arises from the unconventional 2H/fcc heterophase, high-index facets, planar defects, and appropriate alloying of Cu. Impressively, the 2H/fcc Au 99 Cu 1 shows CO Faradaic efficiencies of 96.6% and 92.6% at industrial current densities of 300 and 500 mA cm -2 , respectively, as well as good durability, placing it among the best CO 2 reduction electrocatalysts for CO production. The atomically structural regulation based on phase engineering of nanomaterials (PEN) provides an avenue for the rational design and preparation of high-performance electrocatalysts for various catalytic applications., (© 2023 Wiley-VCH GmbH.)

Controlled construction of bimetallic nanostructures with a well-defined heterophase is of great significance for developing highly efficient nanocatalysts and investigating the structure-dependent catalytic performance. Here, a wet-chemical synthesis method is used to prepare Au@Pd core-shell nanorods with a unique fcc -2H- fcc heterophase ( fcc : face-centered cubic; 2H: hexagonal close-packed with a stacking sequence of "AB"). The obtained fcc -2H- fcc heterophase Au@Pd core-shell nanorods exhibit superior electrocatalytic ethanol oxidation performance with a mass activity as high as 6.82 A mg Pd -1 , which is 2.44, 6.96, and 6.43 times those of 2H-Pd nanoparticles, fcc -Pd nanoparticles, and commercial Pd/C, respectively. The operando infrared reflection absorption spectroscopy reveals a C2 pathway with fast reaction kinetics for the ethanol oxidation on the prepared heterophase Au@Pd nanorods. Our experimental results together with density functional theory calculations indicate that the enhanced performance of heterophase Au@Pd nanorods can be attributed to the unconventional 2H phase, the 2H/ fcc phase boundary, and the lattice expansion of the Pd shell. Moreover, the heterophase Au@Pd nanorods can also serve as an efficient catalyst for the electrochemical oxidation of methanol, ethylene glycol, and glycerol. Our work in the area of phase engineering of nanomaterials (PENs) opens the way for developing high-performance electrocatalysts toward future practical applications.