Strengthening the oxide–metal interfacial synergistic interaction in nanocatalysts is identified as potential strategy to boost intrinsic activities and the availability of active sites by regulating the surface/interface environment of catalysts. Herein, the SnO₂/PtNi concave nanocubes (CNCs) enclosed by high-index facets (HIFs) with tunable SnO₂ composition are successfully fabricated through combining the hydrothermal and self-assembly method. The interfacial interaction between ultrafine SnO₂ nanoparticles and PtNi with HIFs surface structure is characterized by analytical techniques. The as-prepared 0.20%SnO₂/PtNi catalyst exhibits extraordinarily high catalytic performance for ethylene glycol electrooxidation (EGOR) in acidic conditions with specific activity of 3.06 mA/cm², which represents 6.2-fold enhancement compared with the state-of-the-art Pt/C catalyst. Additionally, the kinetic study demonstrates that the strong interfacial interaction between SnO₂ and PtNi not only degrades the activation energy barrier during the process of EGOR but also enhances the CO-resistance ability and long-term stability. This study provides a novel perspective to construct highly efficient and stable electrocatalysts for energy conversions.

Surface engineering has been found to be an efficient strategy to boost the catalytic performance of noble-metal-based nanocatalysts. In this work, a small amount of P was doped to the surface of PtNi concave cube (P-PtNi CNC). Interestingly, the P-PtNi CNC nanocatalyst shows an enhanced methanol oxidation reaction (MOR) performance with achieving 8.19 times of specific activity than that of comercial Pt/C. The electrochemical in situ Fourier transform infrared spectroscopy (FTIR) results reveal that the surface P doping promotes the adsorption energy of OH, enhancing the resistance against CO poisoning. Therefore, the intermediate adsorbed CO (CO_ads) reacted with adsorbed OH (OH_ads) through the Langmuir–Hinshelwood (LH) mechanism to generate CO₂ and release surface active sites for further adsorption. This work provides a promising strategy via the incorporation of non-metallic elements into the PtNi alloys bounded with high-index facets (HIFs) as efficient fuel cell catalysts.

Pt₃Ni alloy structure is an effective strategy to accelerate ethanol oxidation reaction (EOR), while the stability in acid electrolyte is the fatal weakness and the current density still needs to be enhanced. Herein, ultralong Pt₃Ni nanowires tailored by trace Mo (Mo/Pt₃Ni NWs) were successfully synthesized by surfactant free method. The specific activity of the optimized catalyst was 2.66 mA·cm^–2, which is approximately 2.16 and 4.6-fold that of Pt₃Ni NWs and commercial Pt/C catalyst, respectively. Most importantly, the Mo/Pt₃Ni NWs catalyst showed negligible structure degradation after 3,000 cycles (42 h) of durability test in 0.1 M HClO₄ and 0.5 M ethanol, as compared to severe structural collapse and Ni dissolution for the pure Pt₃Ni NWs. The density functional theory (DFT) calculation also confirmed that both the surface and subsurface Mo atom could form Pt-Mo and Ni-Mo bonds with Pt and Ni, which were stronger than Pt-Ni bonds, to pin the Ni atoms in the unstable position and suppress the dissolution of surface Ni. The findings of this study indicate a promising pathway for the design and engineering of durable alloy nanocatalysts for direct ethanol fuel cell applications.

In this paper, we report the fabrication of cobalt-doped de-NO_x catalyst by pyrolyzing an analogous metal-organic framework-74 (MOF-74) containing Fe & Mn. The resulted catalyst exhibits distinctive microstructures of manganese, cobalt, and iron immobilized on N-doped carbon nanotubes (CNTs). It is found through experiments that the trimetallic catalyst Fe ₂Mn₁Co_0.5/CNTs-50 has the best NH₃-selective catalytic reduction (SCR) performance. The Fe₂Mn₁Co_0.5/CNTs-50 exhibited excellent water and sulfur resistance and good stability under the harsh gas environment of 250 °C and/or 170 °C, NO = NH₃ = 1,000 ppm, 8 vol.% O₂, 20 vol.% H₂O, 1,000 ppm SO₂, and gas hourly space velocity (GHSV) = 75,000 h⁻¹. The de-NO_x conversion was maintained about 55% and 25% after 192 h. The water and sulfur resistance performance were much higher than commercial vanadium series catalyst. The highly water and sulfur resistance performance may be attributed to the unique core–shell microstructure and the synergistic effect of manganese, cobalt, and iron which helps reduce the formation for by-products (NH₄HSO₄). This study may promote to explore the development of a high stability catalyst for low-temperature selective catalytic reduction of NO_x with NH₃.

It is generally accepted that the interface effect and surface electronic structure of catalysts have vital impact on catalytic properties. Understanding and tailoring the atomic arrangement of interface structure are of great importance for electrocatalysis. Herein, we proposed a simple method to synthesize etching-PtNiCu nanowires (e-PtNiCu NWs) enclosed by both (110) and (100) facets evolving from PtNiCu nanowires (PtNiCu NWs) mainly with (111) facets by selectively etching process. After acetic acid etching treatment, the e-PtNiCu NWs possess high total proportions (88.3%) of (110) and (100) facets, whereas the (111) facet is dominant in PtNiCu NWs (64%) by qualitatively and quantitatively evaluation. Combining the structure characterizations and performance tests of ethanol electrooxidation reaction (EOR), we find that the e-PtNiCu NWs display remarkably performance for EOR, which is nearly 4.5 times and 1.5 times enhancement compared with the state-of-the-art Pt/C catalyst, as well as 2.2 and 1.4 times of PtNiCu NWs, in specific activity and mass activity, respectively. The improved performance of e-PtNiCu NWs is attributed to synergistic catalytic effect between (110) and (100) facets that not only significantly decreases the onset potentials of adsorbed CO (CO_ads) but also favors the oxidation of CO_ads on the surface of catalyst. Furthermore, thermodynamics and kinetic studies indicate that the synergistic effect of both (110) and (100) facets in e-PtNiCu NWs can decrease the activation energy barrier and facilitate the charge transfer during the reaction. This work provides a promising approach to construct catalysts with tunable surface electronic structure towards efficient electrocatalysis.

Controlled integration of ultrafine metal nanoparticles (MNPs) and metal-organic frameworks (MOFs) has drawn much attention due to their unique physical and chemical properties. However, the development of a one-step strategy for preparing ultrafine MNPs within MOFs still remains a great challenge. Herein, a facile synthetic approach toward the abovementioned composites was developed. In contrast to the conventional approach, these hybrids were prepared by the direct mixing of metal and MOF precursors in the reaction solution assisted by microwave irradiation. Impressively, the Au/MOF-199 composite with uniformly distributed ultrafine Au nanoparticles could be fabricated in only two minutes, and the Au loading could be increased up to a level of 5.13%. The multifunctional Au/MOF-199 catalysts exhibited high turnover numbers (TONs) and turnover frequencies (TOFs) in the three-component coupling reaction of formaldehyde, phenylacetylene, and piperidine (A³-coupling). Owing to the confinement effect of MOF-199, the 5.13%Au/MOF-199 catalyst could be recycled for five runs without serious loss of activity, with no obvious aggregation of Au NPs detected.

A series of novel catalysts consisting of nanosized Au particles confined in micro-mesoporous ZSM-5/SBA-15 (ZSBA) materials with platelet (PL), rod (RD), and hexagonal-prism (HP) morphologies have been synthesized in situ. These catalysts possess both SBA-15 and ZSM-5 structures and exhibit excellent stability of their active sites by confinement of the Au nanoparticles (NPs) within ZSBA. The catalysts have been characterized in depth to understand their structure–property relationships. The gold NP dimensions and the pore structure of the catalysts, which were found to be sensitive to calcination temperature and synthetic conditions, are shown to play vital roles in the reduction of 4-nitrophenol. Au/ZSBA-PL, with short mesochannels (210 nm) and a large pore diameter (6.7 nm), exhibits high catalytic performance in the reduction of 4-nitrophenol, whereas Au/ZSBA-HP and Au/ZSBA-RD, with long mesochannels and relatively smaller pore sizes, show poor catalytic activities. In the case of catalysts with different gold NP sizes, Au/ZSBA-PL-350 with an Au NP diameter of 4.0 nm exhibits the highest reaction rate constant (0.14 min^-1) and turnover frequency (0.0341 s^-1). In addition, the effect of the reaction parameters on the reduction of 4-nitrophenol has been systematically investigated. A possible mechanism for 4-nitrophenol reduction over the Au/ZSBA catalysts is proposed.

The high cost and poor atom utilization efficiency of noble metal catalysts have limited their industrial applications. Herein, we designed CeO₂-supported single Au(Ⅲ) ion catalysts with ultra-low gold loading that can enhance the utilization efficiency of gold atoms and bridge the gap between homogeneous and heterogeneous gold catalysis. These catalysts were highly active and reusable for the reaction of 1, 3-dicarbonyls with alcohols. The catalytic turnover number of CeO₂-supported single Au(Ⅲ) ion catalysts was much higher than that of the homogeneous catalyst NaAuCl₄. In addition, the effects of gold loading and the drying method for the catalysts on the organic reactions were systematically explored. In-depth investigation of the structure–property relationship by highresolution transmission electron microscopy, hydrogen temperature-programmed reduction, X-ray absorption near edge structure analysis, UV–vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy revealed that the isolated Au(Ⅲ) ions were related to the active sites for the synthesis of β-substituted cyclohexenone and that CeO₂ was responsible for yielding ketonic ester.

An ideal metal catalyst requires easy contact with reaction reagents, a large number of exposed active sites, and high stability against leaching or particle agglomeration. Anchoring a metal core inside a porous shell, though scarcely reported, may combine these advantages owing to the integration of the conventional supported metal arrangement into a core@void@shell architecture. However, achieving this is extremely difficult owing to the weak core—shell affinity. Herein, we report, for the first time, an approach to overcome this challenge by increasing the core-shell interaction. In this regard, we synthesized a novel Au@void@periodic mesoporous organosilica (PMO) architecture in which a single Au core is firmly anchored inside the porous shell of the hollow PMO sphere. The non-covalent interactions between the poly(vinylpyrrolidone) (PVP) groups of functionalized Au and ethane moieties of PMO facilitate the movement of the Au core towards the porous shell during the selective alkaline etching of Au@SiO₂@PMO. Shell-anchored Au cores are superior to the suspended cores in the conventional Au@void@PMO in terms of contact with reagents and exposure of active sites, and hence show higher catalytic efficiency for 4-nitrophenol reduction. The methodology demonstrated here provides a new insight for the fabrication of versatile multifunctional nanostructures with cores anchored inside hollow shells.