Yolk-shell Structure Research Articles

"Multi-in-One" Yolk-Shell Structured Nanoplatform Inducing Pyroptosis and Antitumor Immune Response Through Cascade Reactions.

Pyroptosis, a new mode of regulatory cell death,holdsa promising prospect in tumor therapy. The occurrence of pyroptosis can trigger the release of damage-associated molecular patterns (DAMPs) and activate the antitumor immune response. Moreover, enhancing intracellular reactive oxygen species (ROS) generation can effectively induce pyroptosis. Herein, an integrated nanoplatform (hCZAG) based on zeolitic imidazolate framework-8 (ZIF-8) with Cu2+ and Zn2+ as active nodes and glucose oxidase (GOx) loading is constructed to evoke pyroptosis. GOx can effectively elevate intracellular hydrogen peroxide (H2O2) levels to regulate the unfavorable tumor microenvironment (TME). Cu2+ can be reduced to Cu+ by endogenous overexpressed GSH and both Cu2+ and Cu+ can exert Fenton-like activity to promote ROS generation and amplify oxidative stress. In addition, the accumulation of Cu2+ leads to the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT), thus resulting in cuproptosis. Notably, the outburst of ROS induced by hCZAG activates Caspase-1 proteins, leads to the cleavage of gasdermin D (GSDMD), and induces pyroptosis. Pyroptosis further elicits an adaptive immune response, leading to immunogenic cell death (ICD). This study provides effective strategies for triggering pyroptosis-mediated immunotherapy and achieving improved therapeutic effects.

N-doped graphene quantum dot-decorated MOF-derived yolk-shell ZnO/NiO hybrids to boost lithium and sodium ion battery performance

Surface engineering at the nanoscale to obtain robust interface between metal oxides and quantum dots is essential for improving the performance and stability of battery materials. Herein, we designed and prepared novel N-doped graphene quantum dot-modified ZnO/NiO anode materials with a well-defined yolk-shell structure for lithium and sodium-ion batteries. NG QDs were assembled on the ZnO/NiO microspheres using three different coupling strategies: solvothermal, direct adsorption and annealing under N2 atmosphere. The presence of NG QDs deposited on the ZnO/NiO hybrids promoted enhanced electrical conductivity, lower charge-transfer resistance and provides more active sites. As a result, NG-ZnO/NiO_s anode obtained by solvothermal route exhibited high reversible delithiation capacity of 912 mAh/g at 18.6 mA g−1 and excellent cycling performance with the average delithiation capacity of 525 mAh/g at 372 mA g−1 over 400 cycles. Moreover, application of the NG-ZnO/NiO_s elecrode in Na-ion batteries revealed decent electrochemical behavior with capacity values reaching 235 mAh/g at 18.6 mA g−1. Importantly, surface properties, morphology and electrochemical behavior of obtained NG-ZnO/NiO hybrids were dependent on the combination route of NG QDs with ZnO/NiO microspheres indicating that quality of heterojunction between composite components has significant impact on the electrode performance.

Amine-containing yolk-shell structured magnetic organosilica nanocomposite as a highly efficient catalyst for the Knoevenagel reaction.

The yolk-shell structured silica nanocomposites have been considered by many researchers due to their specific physical and chemical properties. These materials have been widely used in adsorption and catalysis processes. Especially, the void space of yolk-shell nanostructures can provide a unique environment for storage, compartmentation, and confinement in host-guest interactions. In this paper, for the first time, the preparation, characterization, and catalytic application of a novel amine-containing magnetic methylene-based periodic mesoporous organosilica with yolk-shell structure (YS-MPMO/pr-NH2) are developed. The magnetic periodic mesoporous organosilica nanocomposite was synthesized through surfactant-directed co-condensation of bis(triethoxysilyl)methane (BTEM) and tetraethoxysilane around Fe3O4 nanoparticles. After Soxhlet extraction, the surface of YS-MPMO nanocomposite was modified with 3-aminopropyl trimethoxysilane to deliver YS-MPMO-pr-NH2 nanocatalyst. This catalyst was characterized by using EDX, FT-IR, VSM, TGA, XRD, nitrogen-sorption, and SEM analyses. The catalytic activity of YS-MPMO/pr-NH2 was studied in the Knoevenagel reaction giving the corresponding products in a high yield and selectivity. The YS-MPMO/pr-NH2 nanocatalyst was recovered and reused at least four times without a significant decrease in efficiency and activity. A leaching test was performed to study the nature of the catalyst during reaction conditions Also, the catalytic performance of our designed nanocomposite was compared with some of the previous catalysts used in the Knoevenagel reaction.

Synthesis of yolk–shell COF with corrole and electrocatalytic property of Co-doped COF for oxygen reduction reaction

Abstract Covalent organic polymers (COP) were synthesized by polymerizing 5,10,15-tris(4-aminophenyl)corrole (TAPC) and terephthalaldehyde in the presence of acetic acid. Yolk–shells and filled structures were obtained after ripening of COP synthesized with low and high acetic acid/TAPC, respectively. The low cross-linking degree of COP synthesized by low acetic acid/TAPC resulted in a yolk–shell structure due to the easy dissolution of the interior. The Co-doped yolk–shell showed higher electrocatalytic activity for the oxygen reduction reaction than the filled structure.

Fabrication of Yolk-Shell Structure with Multifarious Nanoparticles via Double-Layered Encapsulation Strategy.

The post-encapsulation method (such as single-layered encapsulation) is a promising strategy to synthesize yolk-shell structures that protect functional nanoparticles by the molecular sieving effect. However, this method exhibited limited loading capacity and nonuniform encapsulation during the co-encapsulation of various nanoparticles owing to the insufficient surface area for nanoparticle attachment. To address these limitations, we proposed a double-layered encapsulation method comprising an increased number of silica template layers and separate attachment of multifarious nanoparticles to different layers. Compared with conventional methods, this strategy can precisely adjust the ratio of encapsulated nanoparticles and increase the loading amount, which improves the functionality of yolk-shell structures, such as the photothermal properties of gold nanoparticle-encapsulated yolk-shell structures (∼69%). We describe, for the first time, the precise control of the ratio of encapsulated nanoparticles and the loading of numerous nanoparticles. Consequently, this strategy has significant potential for various applications of yolk-shell structures.

Semi-Coherent Heterointerface Engineering via In Situ Phase Transition for Enhanced Sodium/Lithium-Ions Storage.

To improve ion transport kinetics and electronic conductivity between the different phases in sodium/lithium-ion battery (LIB/SIB) anodes, heterointerface engineering is considered as a promising strategy due to the strong built-in electric field. However, the lattice mismatch and defects in the interphase structure can lead to large grain boundary resistance, reducing the ion transport kinetics and electronic conductivity. Herein, monometallic selenide Fe3Se4-Fe7Se8 semi-coherent heterointerface embedded in 3D connected Nitrogen-doped carbon yolk-shell matrix (Fe3Se4-Fe7Se8@NC) is obtained via an in situ phase transition process. Such semi-coherent heterointerface between Fe3Se4 and Fe7Se8 shows the matched interfacial lattice and strong built-in electric field, resulting in the low interface impedance and fast reaction kinetics. Moreover, the yolk-shell structure is designed to confine all monometallic selenide Fe3Se4-Fe7Se8 semi-coherent heterointerface nanoparticles, improving the structural stability and inhibiting the volume expansion effect. In particular, the 3D carbon bridge between multi-yolks shell structure improves the electronic conductivity and shortens the ion transport path. Therefore, the efficient reversible pseudocapacitance and electrochemical conversion reaction are enabled by the Fe3Se4-Fe7Se8@NC, leading to the high specific capacity of 439mAhg-1 for SIB and 1010mAhg-1 for LIB. This work provides a new strategy for constructing heterointerface of the anode for secondary batteries.

Cobalt-vanadium sulfide yolk-shell nanocages from surface etching and ion-exchange of ZIF-67 for ultra-high rate-capability sodium ion battery

Development of high-performance metal sulfides anode materials is a great challenge for sodium-ion batteries (SIBs). In this work, a cobalt-based imidazolate framework (ZIF-67) were firstly synthesized and applied as precursor. After the successive surface etching, ion exchange and sulfidation processes, the final cobalt-vanadium sulfide yolk-shell nanocages were obtained (CoS2/VS4@NC) with VS4 shell and CoS2 yolk encapsulated into nitrogen doped carbon frameworks. This yolk-shell nanocage structure effectively increases the specific surface area and provides enough space for inhibiting the volume change during charge/discharge processes. Besides, the nitrogen doped carbon skeleton greatly improves the ionic conductivity and facilitates ion transport. When used as the anode materials for SIBs, the yolk-shell nanocages of CoS2/VS4@NC electrode exhibits excellent rate capability and stable cycle performance. Notably, it displays a long-term cycling stability with excellent capacity of 417.28 mA h g−1 after 700 cycles at a high current density of 5 A/g. This developed approach here provides a new route for the design and synthesis of various yolk-shell nanocages nanomaterials from enormous MOFs with multitudinous compositions and morphologies and can be extended to the application into other secondary batteries and energy storage fields.

Design synthesis of ZSM-5 zeolite with yolk-shell structure by Oswald ripening for aromatization of coal-oil co-refining oils

Aiming to improve the catalytic performance of HZSM-5 in the catalytic conversion of coal-oil co-refining oil, a range of zeolite catalysts (HZ5-xD) were prepared by adjusting the recrystallization times of dissolution–recrystallization of HZSM-5 basing on the Oswald ripening mechanism. The results show that HZ5-xD processes more easily accessible active sites and mixed microporous-mesoporous structures. Larger pore size and moderate acidity were beneficial for the generation of benzene, toluene, ethylbenzene and xylene (BTEX). The selectivity and yield of reached as high as 29.76 % and 236.83 mg·g−1 over HZ5-2D at 700 °C, respectively. Both HZSM-5 and HZ5-xD demonstrate high selectivity to C3 gaseous hydrocarbons, likely due to the obedience of the carbenium ion mechanism. HZ5-2D still demonstrated more excellent catalytic performance than HZSM-5 after five regenerations. Collectively, these finding illustrates the broad application potential of Oswald ripening in special morphologies of zeolite to improve the conversion efficiency of coal tar to BTEX.

Facilely tunable dodecahedral polyoxometalate framework loaded with mono- or bimetallic sites for efficient photocatalytic CO2 reduction

Utilizing solar energy to drive the conversion of CO2 into high-value chemicals emerged as a promising approach to decrease CO2 emission. Yolk-shell or hollow structure have drawn much attention for photocatalytic CO2 reduction, owing to their efficient CO2 trapping and more active sites exposing. In this study, we employed a simple method to regulate the morphological evolution of K3PW12O40 dodecahedra. After annealing, mono-/bimetallic active species are homogeneously dispersed on K3PW12O40 framework forming PW12 @Co and PW12 @CoNi, which exhibit good CO production rates of 11.2 and 15.1 μmol/h, respectively, with selectivity of 90.7% and 92.6%. The differences in the activity and selectivity of CO2RR are attributed to the morphology variations of POM and the influence of mono-/bimetallic species. These results are confirmed through the analysis of SEM, TEM, N2 and CO2 adsorption/desorption, PL, EIS and SPV characterizations. In-situ DRIFTS and DFT provide further support for the formation and transformation of intermediate products.

Design yolk-shelled FeCo layered double hydroxide via a “one-stone-two-birds” strategy for oxygen evolution reaction

In order to meet the demands for green and sustainable energy, it is imperative to develop high-performance, cost-effective, and environmentally friendly electrocatalysts to enhance the oxygen evolution reaction (OER). In this regard, we introduce a novel reconstruction strategy, involving crystallization, growth, and etching processes, to synthesize a highly efficient electrocatalyst for the OER. A hydrothermal process was initially employed to synthesize materials of institute Lavoisier framework-88 (MIL-88) as a self-engaged precursor, which was subsequently transformed into hierarchical FeCo layered double hydroxide (LDH)@zeolitic imidazolate framework-67 (ZIF-67). Additionally, a “one-stone-two-birds” strategy was employed to create the yolk-shelled FeCo-LDH composite (denoted as YS FeCo-LDH) by etching FeCo-LDH@ZIF-67. On one hand, ZIF-67 can be gradually etched by the H+ ions generated through the hydrolysis of [Fe(C2O4)3]3−. On the other hand, simultaneously released Fe3+ and Co2+ co-precipitate with OH–/C2O42−, resulting in the formation of the FeCo-LDH shells. Benefiting from the yolk-shell structure, excellent microstructural integrity, efficient mass transport within interlinked nanocages, and abundant active sites, the YS FeCo-LDH catalyst exhibits remarkable electrocatalytic performance in the OER. This work represents a significant advancement in the development of high-efficiency yolk-shelled hollow electrocatalysts.

Yolk-shell construction of Co0.7Fe0.3 modified with dual carbon for broadband microwave absorption

The rational and effective combination of multicomponent materials and the design of subtle microstructure for efficient microwave absorption are still challenging. In this study, carbon-coated CoFe with heterogeneous interfaces was space-restricted in the void space of hollow mesoporous carbon spheres through a facile approach involving electrostatic adsorption and annealing, and a high-performance microwave absorber (MAs) (denoted as Co0.7Fe0.3@C@void@C) was successfully prepared. The heterostructure, three-dimensional lightweight porous morphology, and electromagnetic synergy strategy enabled the Co0.7Fe0.3@C@void@C material with yolk-shell structure to exhibit surprising microwave absorption properties. When the annealing temperature and filler loading were 550° C and 15 wt%, respectively, the composites exhibited an effective absorption bandwidth (EAB) of 7.16 GHz at 2.48 mm and a minimum reflection loss of −24.1 dB at 2.11 mm. A maximum EAB of 7.21 GHz at 2.37 mm could be achieved for the composite prepared with an annealing temperature of 650° C. In addition, radar cross-section experiments demonstrated, the potential practical applicability of Co0.7Fe0.3@C@void@C. This work expands a new avenue to develop high-performance and lightweight MAs with ingenious microstructure.

Yolk–shell Ni–Co bimetallic nitride/oxide heterostructures as high‐performance electrode of all‐solid‐state supercapacitor

Hierarchical core–shell structure is benefit for the fast diffusion and bulk storage of electron/ion while metal nitrides (MN) exhibit metal‐like behavior with excellent conductivity. Herein, nickel cobalt glycerate solid spheres (NiCo‐G) and nickel cobalt glycerate yolk–shell structure (NiCo‐GYS) were successfully synthesized via solvothermal reactions, accompanied by annealing using urea as a cheap and convenient nitrogen source to obtain metal nitride/bimetallic oxide core–shell heterostructure (NiCoNO). Excellent specific capacitance of 1878 F g−1 at 1 A g−1 is displayed by the prepared NiCoNO. Amazingly, the distinct core–shell construction guarantees high stability during the charge/discharge operation. NiCoNO maintains an 83.9% specific capacitance after 5000 cycles at 10 A g−1. Furthermore, the all‐solid‐state hybrid supercapacitor was assembled using NiCoNO cathode and active carbon (AC) anode components. The device has an excellent capacitive retention rate of 81.1% after 5000 cycles at 10 A g−1 and a good energy density of 64.2 Wh kg−1 at a power density of 900 Wh kg−1. A light‐emitting diode (LED) bulb can be lighted for 3 min, indicating the promising practical application prospect of the supercapacitor.

Constructing three-dimensional architectures to design advanced anodes materials for sodium-ion batteries: from nanoscale to microscale

Sodium-ion batteries (SIBs) are emerging as a possible substitute for lithium-ion batteries (LIBs) in low-cost and large-scale electrochemical energy storage systems owing to the lack of lithium resources. The properties of SIBs are correlated to the electrode materials, while the performance of electrode materials is significantly affected by the morphologies. In recent years, several kinds of anode materials involving carbon-based anodes, titanium-based anodes, conversion anodes, alloy-based anodes, and organic anodes have been systematically researched to develop high-performance SIBs. Nanostructures have huge specific surface areas and short ion diffusion pathways. However, the excessive solid electrolyte interface film and worse thermodynamic stability hinder the application of nanomaterials in SIBs. Thus, the strategies for constructing three-dimensional (3D) architectures have been developed to compensate for the flaws of nanomaterials. This review summarizes recent achievements in 3D architectures, including hollow structures, core-shell structures, yolk-shell structures, porous structures, and self-assembled nano/micro-structures, and discusses the relationship between the 3D architectures and sodium storage properties. Notably, the intention of constructing 3D architectures is to improve materials performance by integrating the benefits of various structures and components. The development of 3D architecture construction strategies will be essential to future SIB applications.

The energy storage application of core-/yolk–shell structures in sodium batteries

Materials with a core–shell and yolk–shell structure have attracted considerable attention owing to their attractive properties for application in Na batteries and other electrochemical energy storage systems.

Exploring the potential of CuCoFeTe@CuCoTe yolk-shelled microrods in supercapacitor applications.

Driven by their excellent conductivity and redox properties, metal tellurides (MTes) are increasingly capturing the spotlight across various fields. These properties position MTes as favorable materials for next-generation electrochemical devices. Herein, we introduce a novel, self-sustained approach to creating a yolk-shelled electrode material. Our process begins with a metal-organic framework, specifically a CoFe-layered double hydroxide-zeolitic imidazolate framework67 (ZIF67) yolk-shelled structure (CFLDH-ZIF67). This structure is synthesized in a single step and transformed into CuCoLDH nanocages. The resulting CuCoFeLDH-CuCoLDH yolk-shelled microrods (CCFLDH-CCLDHYSMRs) are formed through an ion-exchange reaction. These are then converted into CuCoFeTe-CuCoTe yolk-shelled microrods (CCFT-CCTYSMRs) by a tellurization reaction. Benefiting from their structural and compositional advantages, the CCFT-CCTYSMR electrode demonstrates superior performance. It exhibits a fabulous capacity of 1512 C g-1 and maintains an impressive 84.45% capacity retention at 45 A g-1. Additionally, it shows a remarkable capacity retention of 91.86% after 10 000 cycles. A significant achievement of this research is the development of an activated carbon (AC)||CCFT-CCTYSMR hybrid supercapacitor. This supercapacitor achieves a good energy density (Eden) of 63.46 W h kg-1 at a power density (Pden) of 803.80 W kg-1 and retains 88.95% of its capacity after 10 000 cycles. These results highlight the potential of telluride-based materials in advanced energy storage applications, marking a step forward in the development of high-energy, long-life hybrid supercapacitors.

Structural engineering in hierarchical nanoarchitectures of metal-organic frameworks and their derivatives.

Metal-organic frameworks (MOFs) have attracted much attention owing to their tuneable structures, high surface areas, and good functionalization. Nanoreactors derived from various MOFs are now widely used in heterogeneous catalysis, electrocatalysis and photocatalysis. The nanoarchitectures of MOFs and their derivatives have a great impact on mass and energy transfer pathways, thus affecting the activity and selectivity of the catalysts. In this review, we intend to provide a universal survey of reported methods to synthesize MOF-based core-satellite, core-shell, yolk-shell and hollow-shell structures or their derivatives in recent years and present a continuous evolution among them. We hope that this review could provide some perspectives for exploring new facile methods to prepare different hierarchical nanoarchitectures of MOFs or their derivatives.

From nano- to macroarchitectures: designing and constructing MOF-derived porous materials for persulfate-based advanced oxidation processes.

Persulfate-based advanced oxidation processes (PS-AOPs) have gained significant attention as an effective approach for the elimination of emerging organic contaminants (EOCs) in water treatment. Metal-organic frameworks (MOFs) and their derivatives are regarded as promising catalysts for activating peroxydisulfate (PDS) and peroxymonosulfate (PMS) due to their tunable and diverse structure and composition. By the rational nanoarchitectured design of MOF-derived nanomaterials, the excellent performance and customized functions can be achieved. However, the intrinsic fine powder form and agglomeration ability of MOF-derived nanomaterials have limited their practical engineering application. Recently, a great deal of effort has been put into shaping MOFs into macroscopic objects without sacrificing the performance. This review presents recent advances in the design and synthetic strategies of MOF-derived nano- and macroarchitectures for PS-AOPs to degrade EOCs. Firstly, the strategies of preparing MOF-derived diverse nanoarchitectures including hierarchically porous, hollow, yolk-shell, and multi-shell structures are comprehensively summarized. Subsequently, the approaches of manufacturing MOF-based macroarchitectures are introduced in detail. Moreover, the PS-AOP application and mechanisms of MOF-derived nano- and macromaterials as catalysts to eliminate EOCs are discussed. Finally, the prospects and challenges of MOF-derived materials in PS-AOPs are discussed. This work will hopefully guide the design and development of MOF-derived porous materials in SR-AOPs.

Graphene-wrapped yolk-shell of silica-cobalt oxide as high-performing anode for lithium-ion batteries.

Silica (SiO2) shows promise as anode material for lithium-ion batteries due to its low cost, comparable lithium storage discharge potential and high theoretical capacity (approximately 1961 mA h g-1). However, it is plagued by issues of low electrochemical activity, low conductivity and severe volume expansion. To address these challenges, we initially coat SiO2 with CoO, followed by introducing SiO2@CoO into graphene sheets to fabricate an anode composite material (SiO2@CoO/GS) with uniformly dispersed particles and a 3D graphene wrapped yolk-shell structure. The coating of CoO on SiO2 converted the negative surface charge of SiO2 to positive, enabling effective electrostatic interactions between SiO2@CoO and graphene oxide sheets, which provided essential prerequisites for synthesizing composite materials with uniformly dispersed particles and good coating effects. Furthermore, the Co-metal formed during the charge-discharge process can act as a catalyst and electron transfer medium, activating the lithium storage activity of SiO2 and enhancing the conductivity of the electrode, conclusively achieving a higher lithium storage capacity. Ultimately, due to the activation of SiO2 by Co-metal during cycling and the excellent synergistic effect between SiO2@CoO and graphene, SiO2@CoO/GS delivers a high reversible capacity of 738 mA h g-1 after 500 cycles at 200 mA g-1. The product also demonstrates excellent rate performance with a reversible capacity of 206 mA h g-1 at a high specific current of 12.8 A g-1. The outstanding rate performance of SiO2@CoO/GS may be ascribed to the pseudo-capacitive contribution at high specific current upon cycling.

Reactant enrichment in yolk-shell structured Pd/TiN nanoreactors for boosting electrocatalytic hydrodechlorination performance

Enhancing the enrichment behavior of low-concentration chlorinated organic pollutants remains a significant challenge in electrocatalytic hydrodechlorination (EHDC) technology. Metal-loaded hollow nanoarchitecture has emerged as a promising nanoreactor to improve reaction enrichment behavior because of its tailorable microenvironments and electronic properties. Herein, a structural engineering strategy is developed to synthesize yolk-shell structured TiN spheres supported Pd nanoreactors (Pd/YS-TiN) with confined mesoscopic spaces. Characterization by multiple techniques reveals that the yolk-shell structure of YS-TiN, with high specific surface area (139.0 m2/g) and appropriately mesoporosity (6.9 nm), exposes numerous Pd nanoparticles (∼4.0 nm) on outer/inner surface of the shell and yolk-core solid sphere, ensuring an efficient utilization of active sites for enhancing the 2,4-DCP detoxification. Consequently, the structurally optimized Pd/YS-TiN nanoreactor consistently displays maximum reaction kinetics, dechlorination degree, faradaic current density, H* utilization and product selectivity, surpassing hollow TiN-supported Pd and Pd/C catalysts. The super EHDC performance of 91.8 % 2,4-DCP conversion, a specific activity of 1.68 min−1 molPd−1, and a mass activity of 6.06 min−1 gPd−1 is obtained at −0.85 V and 180 min, outperforming most reported catalysts. Combining experimental and density functional theory results, the exceptional reaction enrichment behavior of Pd/YS-TiN originates from (1) alleviating the overstrong adsorption of product phenol through strong metal-support interactions and (2) enhancing mass transport efficiency facilitated by the local concentration gradient and mesoporous shell. This study elucidates how metal-support interactions and mass transport synergistically enhance reaction enrichment behavior, showcasing potential benefits in environmental remediation applications.

Integrated Optimization of Crystal Facets and Nanoscale Spatial Confinement toward the Boosted Catalytic Performance of Pd Nanocrystals.

Tuning the surface chemical property and the local environment of nanocrystals is crucial for realizing a high catalytic performance in various reactions. Herein, we aim to elucidate the structure sensitivity of Pd facets on the surface catalytic hydrogenation reaction and to identify what role the nanoconfinement effect plays in the catalytic properties of Pd nanocrystal catalysts. By controlling the coating structures of mesoporous silica (mSiO2) on Pd nanocrystals with different exposed facets that include {100}, {111}, and {hk0}, we present a series of Pd@mSiO2 nanoreactors in core-shell and yolk-shell structures and the discovery of a partial-coated structure, which can provide different types of nanoconfinement, and we propose a seed size-dominated growth mechanism. We demonstrate that a superior activity was exhibited in Pd nanocrystals enclosed by the {hk0} facet as compared to the Pd{100} and Pd{111} facets, and substantially enhanced efficiency and stability were achieved in Pd@mSiO2 particles with yolk-shell structures, indicating a crucial superiority of optimizing the configuration of crystal facets and nanoconfinement. Our study provides an efficient strategy to rationally design and optimize nanocatalysts for promoting catalytic performance.