Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the effica...Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.展开更多
Co-catalysts decorations provide unique opportunity in promoting the photocatalytic water splitting performance of graphite carbon nitride(g-C_(3)N_(4))system,while mechanistic understanding of this complex catalytic ...Co-catalysts decorations provide unique opportunity in promoting the photocatalytic water splitting performance of graphite carbon nitride(g-C_(3)N_(4))system,while mechanistic understanding of this complex catalytic network remains elusive.Here,taking the single-atom-based photocatalysts(M1-g-C_(3)N_(4))as an unprecedented simplified model system,we theoretically tracked the photocatalytic kinetics for a comprehensive understanding of the photocatalytic process and afforded the descriptorαS1-T1/αT1-S0(ratio of the extent of S1-T1 and T1-S0 state mixing)andΔGH^(*)(hydrogen adsorpti on free energy)for rational screening of photocatalysts.The targeted Fe1-g-C_(3)N_(4)yields an excellent H_(2)evolution rate(ca.3.2⋅mmol⋅gcat^(-1)⋅h^(-1)under full arc),two order of magnitude improvement relative to pristine g-C_(3)N_(4)counterpart and also outperforms other representative 3d-transition-metal-based photocatalysts.This work presents a comprehensive understanding of the essential role of isolated atomic sites in the photocatalytic course and sheds light on the design of photocatalysts from both photophysical and photochemical aspects.展开更多
The nickel-based superconductivity provides a fascinating new platform to explore high-Tc superconductivity.As the infinite-layer nickelates are obtained by removing the apical oxygens from the precursor perovskite ph...The nickel-based superconductivity provides a fascinating new platform to explore high-Tc superconductivity.As the infinite-layer nickelates are obtained by removing the apical oxygens from the precursor perovskite phase,the crystalline quality of the perovskite phase is crucial in synthesizing high quality superconducting nickelates.Especially,cation-related defects,such as the Ruddlesden–Popper-type(RP-type)faults,are unlikely to disappear after the topotactic reduction process and should be avoided during the growth of the perovskite phase.Herein,using reactive molecular beam epitaxy,we report the atomic-scale engineering of the interface structure and demonstrate its impact in reducing crystalline defects in Nd-based nickelate/SrTiO_(3) heterostructures.A simultaneous deposition of stoichiometric Nd and Ni directly on SrTiO_(3) substrates results in prominent Nd vacancies and Ti diffusion at the interface and RP-type defects in nickelate films.In contrast,inserting an extra[NdO]monolayer before the simultaneous deposition of Nd and Ni forms a sharp interface and greatly eliminates RP-type defects in nickelate films.A possible explanation related to the polar discontinuity is also discussed.Our results provide an effective method to synthesize high-quality precursor perovskite phase for the investigation of the novel superconductivity in nickelates.展开更多
Atomically dispersed nanozymes have garnered immense attention within the biomedical field,while precisely designing these nanozymes and elucidating their intricate structure-performance relationships of their structu...Atomically dispersed nanozymes have garnered immense attention within the biomedical field,while precisely designing these nanozymes and elucidating their intricate structure-performance relationships of their structures and antibacterial performance remain the formidable challenges.Herein,we fabricated defect-rich graphene supported layered Ir cluster nanozymes for antibacterial applications.Steady-state kinetic experiments revealed that the layered Ir clusters exhibited the higher catalytic efficiency of 1.16 mM^(−1)·s^(−1)with 3,3′,5,5′-tetramethylbenzidine(TMB)and 0.18 mM^(−1)·s^(−1)with H_(2)O_(2),compared to Ir nanoparticle(0.55 and 0.1 mM^(−1)·s^(−1))and the atomically dispersed Ir single-atom nanozyme(SAzyme)(0.3 and 0.039 mM^(−1)·s^(−1))and other previously reported single-atom nanozymes.Moreover,both experimental results and density functional theory studies disclosed that the layered Ir clusters exhibited the enhanced ability to facilitate the conversion of hydrogen peroxide into hydroxyl free radicals,signifying the higher catalytic efficiency than that on Ir nanoparticles and Ir single-atoms.Notably,the Ir cluster nanozyme with robust peroxidase-like activity had 100%antimicrobial rate against E.coli and S.aureus,underscoring its potential applications in antibacterial fields.展开更多
The pursuit of energy conservation and environmental protection has always been a hot topic in the catalytic fields,which is inseparable from the rational designing of efficient catalysts and an in-depth understanding...The pursuit of energy conservation and environmental protection has always been a hot topic in the catalytic fields,which is inseparable from the rational designing of efficient catalysts and an in-depth understanding of the catalytic reaction mechanism.In this work,fully-exposed Pt clusters were fabricated on the atomically dispersed Sn decorated nanodiamond/graphene(Sn-ND@G)hybrid support and employed for direct dehydrogenation(DDH)of ethylbenzene(EB)to styrene(ST).The detailed structural characterizations revealed the fully-exposed Pt clusters were stabilized on Sn-ND@G,assisted by the spatial separation of atomically dispersed Sn species.The as-prepared Pt/Sn-ND@G catalyst showed enhanced ST yield(136.2 molEB·molpt-1·h-1 EB conversion rate and 99.7%ST selectivity)and robust long-term stability at 500℃for the EB DDH reaction,compared with the traditional ND@G supported Pt nanoparticle catalyst(Pt/ND@G).The ST prefers to desorb from the fully-exposed Pt clusters,resulting in the enhanced DDH catalytic performance of the Pt/Sn-ND@G catalyst.The present work paves a new way for designing highly dispersed and stable supported metal catalysts for DDH reactions.展开更多
Nanocatalysts are likely to contain undetected single-atom components,which may have been ignored but have significant effect in catalytic reactions.Herein,we report a catalyst composed of Mo single atoms(SAs)and MoO_...Nanocatalysts are likely to contain undetected single-atom components,which may have been ignored but have significant effect in catalytic reactions.Herein,we report a catalyst composed of Mo single atoms(SAs)and MoO_(2)nanoparticles(NPs)(MoSAs-MoO_(2)@NC),which is an exact model to understand how the SAs contribute to the nanocatalyst.Both experimental results and the density functional theory calculations reveal that Mo SAs on nitrogen-doped carbon provides the reaction zone for nitro reduction,while MoO_(2)is the active site for decomposing hydrazine hydrate to produce H*.Thanks to the synergy between Mo SAs and MoO_(2)NPs,this catalyst exhibits noble metal-like catalytic activity(100%conversion at 4 min)for the dechlorination-proof transfer hydrogenation.Additionally,the hydrogen migration on the catalyst is verified by the electrochemical tests in the absence of a hydrogen source.This work provides a model for further study on the coexistence of single atoms in nanoparticle catalysts.展开更多
We report on emergence of an abnormal electronic polarization in twisted double bilayer WSe_(2) in antiparallel interface stacking geometry,where local centrosymmetry of atomic registries at the twist interface does n...We report on emergence of an abnormal electronic polarization in twisted double bilayer WSe_(2) in antiparallel interface stacking geometry,where local centrosymmetry of atomic registries at the twist interface does not favor the spontaneous electronic polarizations as recently observed in the parallel interface stacking geometry.The unconventional ferroelectric behaviors probed by electronic transport measurement occur at half filling insulating states at 1.5 K and gradually disappear at about 40 K.Single band Hubbard model based on the triangular moirélattice and the interlayer charge transfer controlled by insulating phase transition are proposed to interpret the formation of electronic polarization states near half filling in twisted WSe_(2) devices.Our work highlights the prominent role of many-body electronic interaction in fostering novel quantum states in moiré-structured systems.展开更多
基金supported by the National Key R&D Program of China (2021YFA1502802)the National Natural Science Foundation of China (U21B2092, 22202213, 22402210, 22502215, 22502214, 22572200, and 22579171)+3 种基金the International Partnership Program of Chinese Academy of Sciences (172GJHZ2022028MI)the Shenyang Bureau of Science and Technology (24-213-3-25)the Natural Science Foundation of Liaoning Province (2025BS0153)Zhongke Technology Achievement Transfer and Transformation Center of Henan Province 2025119
文摘Single-atom catalysts(SACs)have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency,distinctive geometric,and electronic configurations.However,the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites.Herein,we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene(ND@G)for CO oxidation.The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency(TOF)of 17.6.10^(-2)s^(-1)at significantly lower temperature(30℃),achieving a tenfold increase in TOF compared to singleatom Pt1/ND@G catalyst(1.5.10^(-2)s^(-1))and surpassing to previously reported Pt-based catalysts under similar conditions.Moreover,the catalyst demonstrates excellent stability,maintaining its activity for 40 h at 80℃without significant deactivation.The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O_(2),and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites.The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.
基金supported by the National Natural Science Foundation of China(Grant Nos.51773025 and 22002013)the Fundamental Research Funds for the Central Universities(DUT20RC(3)021)+1 种基金the Natural Foundation of Liaoning Province(Materials Joint Foundation,Grant No.20180510027)The authors thank NSRL(BL12Ba),BSRF(1W1B),and SSRF(BL11B)for the synchrotron radiation beam time.
文摘Co-catalysts decorations provide unique opportunity in promoting the photocatalytic water splitting performance of graphite carbon nitride(g-C_(3)N_(4))system,while mechanistic understanding of this complex catalytic network remains elusive.Here,taking the single-atom-based photocatalysts(M1-g-C_(3)N_(4))as an unprecedented simplified model system,we theoretically tracked the photocatalytic kinetics for a comprehensive understanding of the photocatalytic process and afforded the descriptorαS1-T1/αT1-S0(ratio of the extent of S1-T1 and T1-S0 state mixing)andΔGH^(*)(hydrogen adsorpti on free energy)for rational screening of photocatalysts.The targeted Fe1-g-C_(3)N_(4)yields an excellent H_(2)evolution rate(ca.3.2⋅mmol⋅gcat^(-1)⋅h^(-1)under full arc),two order of magnitude improvement relative to pristine g-C_(3)N_(4)counterpart and also outperforms other representative 3d-transition-metal-based photocatalysts.This work presents a comprehensive understanding of the essential role of isolated atomic sites in the photocatalytic course and sheds light on the design of photocatalysts from both photophysical and photochemical aspects.
基金supported by the National Key Projects for Research and Development of China(Grant No.2022YFA1402502 and 2021YFA1400400)the National Natural Science Foundation of China(Grant No.11861161004)+2 种基金the Fundamental Research Funds for the Central Universities(Grant No.0213–14380221)the Research Grants Council of Hong Kong(Grant No.N PolyU531/18)the Hong Kong Polytechnic University(Grant No.ZVRP)。
文摘The nickel-based superconductivity provides a fascinating new platform to explore high-Tc superconductivity.As the infinite-layer nickelates are obtained by removing the apical oxygens from the precursor perovskite phase,the crystalline quality of the perovskite phase is crucial in synthesizing high quality superconducting nickelates.Especially,cation-related defects,such as the Ruddlesden–Popper-type(RP-type)faults,are unlikely to disappear after the topotactic reduction process and should be avoided during the growth of the perovskite phase.Herein,using reactive molecular beam epitaxy,we report the atomic-scale engineering of the interface structure and demonstrate its impact in reducing crystalline defects in Nd-based nickelate/SrTiO_(3) heterostructures.A simultaneous deposition of stoichiometric Nd and Ni directly on SrTiO_(3) substrates results in prominent Nd vacancies and Ti diffusion at the interface and RP-type defects in nickelate films.In contrast,inserting an extra[NdO]monolayer before the simultaneous deposition of Nd and Ni forms a sharp interface and greatly eliminates RP-type defects in nickelate films.A possible explanation related to the polar discontinuity is also discussed.Our results provide an effective method to synthesize high-quality precursor perovskite phase for the investigation of the novel superconductivity in nickelates.
基金supported by the National Natural Science Foundation of China(Nos.22072162,U21B2092,22402210,22202213,and 21961160722)International Partnership Program of Chinese Academy of Sciences(No.172GJHZ2022028MI)+2 种基金Shenyang Young Talents Program(No.RC220155)Natural Science Foundation of Liaoning Province(No.2024-MS-05)Liaoning BaiQianWan Talents Program and Guangxi Collaborative Innovation Centre of Structure and Property for New Energy and Materials,Science Research,Technology Development Project of Guilin(No.20210102-4)。
文摘Atomically dispersed nanozymes have garnered immense attention within the biomedical field,while precisely designing these nanozymes and elucidating their intricate structure-performance relationships of their structures and antibacterial performance remain the formidable challenges.Herein,we fabricated defect-rich graphene supported layered Ir cluster nanozymes for antibacterial applications.Steady-state kinetic experiments revealed that the layered Ir clusters exhibited the higher catalytic efficiency of 1.16 mM^(−1)·s^(−1)with 3,3′,5,5′-tetramethylbenzidine(TMB)and 0.18 mM^(−1)·s^(−1)with H_(2)O_(2),compared to Ir nanoparticle(0.55 and 0.1 mM^(−1)·s^(−1))and the atomically dispersed Ir single-atom nanozyme(SAzyme)(0.3 and 0.039 mM^(−1)·s^(−1))and other previously reported single-atom nanozymes.Moreover,both experimental results and density functional theory studies disclosed that the layered Ir clusters exhibited the enhanced ability to facilitate the conversion of hydrogen peroxide into hydroxyl free radicals,signifying the higher catalytic efficiency than that on Ir nanoparticles and Ir single-atoms.Notably,the Ir cluster nanozyme with robust peroxidase-like activity had 100%antimicrobial rate against E.coli and S.aureus,underscoring its potential applications in antibacterial fields.
基金supported by the National Key Research and Development Program of China(No.2021YFA1502802)the National Natural Science Foundation of China(Nos.21961160722,92145301,U21B2092,22072162,and 91845201)+5 种基金the Liaoning Revitalization Talents Program(No.XLYC1907055)Natural Science Foundation of Liaoning Province(No.2021-MS001)IMR Innovation Fund(No.2022-PY05)Dalian National Lab for Clean Energy(No.DNL Cooperation Fund 202001)the Sinopec China.N.W.hereby acknowledges the funding support from the Research Grants Council of Hong Kong(Nos.C6021-14E,N_HKUST624/19,and 16306818)The XAS experiments were conducted in Shanghai Synchrotron Radiation Facility(SSRF)。
文摘The pursuit of energy conservation and environmental protection has always been a hot topic in the catalytic fields,which is inseparable from the rational designing of efficient catalysts and an in-depth understanding of the catalytic reaction mechanism.In this work,fully-exposed Pt clusters were fabricated on the atomically dispersed Sn decorated nanodiamond/graphene(Sn-ND@G)hybrid support and employed for direct dehydrogenation(DDH)of ethylbenzene(EB)to styrene(ST).The detailed structural characterizations revealed the fully-exposed Pt clusters were stabilized on Sn-ND@G,assisted by the spatial separation of atomically dispersed Sn species.The as-prepared Pt/Sn-ND@G catalyst showed enhanced ST yield(136.2 molEB·molpt-1·h-1 EB conversion rate and 99.7%ST selectivity)and robust long-term stability at 500℃for the EB DDH reaction,compared with the traditional ND@G supported Pt nanoparticle catalyst(Pt/ND@G).The ST prefers to desorb from the fully-exposed Pt clusters,resulting in the enhanced DDH catalytic performance of the Pt/Sn-ND@G catalyst.The present work paves a new way for designing highly dispersed and stable supported metal catalysts for DDH reactions.
基金supported by the National Key R&D Program of China(Nos.2021YFA1502802 and 2020YFA0406101)the National Natural Science Foundation of China(Nos.21961160722,21872020,22072162,91845201,and 21701168)+3 种基金the Liaoning Revitalization Talents Program XLYC1907055Natural Science Foundation of Liaoning Province(No.2021-MS-001)Dalian National Lab for Clean Energy(DNL Cooperation Fund 202001)Dalian high level talent innovation project(No.2019RQ063).
文摘Nanocatalysts are likely to contain undetected single-atom components,which may have been ignored but have significant effect in catalytic reactions.Herein,we report a catalyst composed of Mo single atoms(SAs)and MoO_(2)nanoparticles(NPs)(MoSAs-MoO_(2)@NC),which is an exact model to understand how the SAs contribute to the nanocatalyst.Both experimental results and the density functional theory calculations reveal that Mo SAs on nitrogen-doped carbon provides the reaction zone for nitro reduction,while MoO_(2)is the active site for decomposing hydrazine hydrate to produce H*.Thanks to the synergy between Mo SAs and MoO_(2)NPs,this catalyst exhibits noble metal-like catalytic activity(100%conversion at 4 min)for the dechlorination-proof transfer hydrogenation.Additionally,the hydrogen migration on the catalyst is verified by the electrochemical tests in the absence of a hydrogen source.This work provides a model for further study on the coexistence of single atoms in nanoparticle catalysts.
基金supported by the National Key R&D Program of China(2020YFA 0309600)the Hong Kong Research Grants Council(AoE/P-701/20,C6025-19G,16305919 ECS26302118,16303720,16305019,16306220 and N_HKUST626/18)+1 种基金the National Natural Science Foundation of China(NSFC20SC07)the William Mong Institute of Nano Science and Technology.
文摘We report on emergence of an abnormal electronic polarization in twisted double bilayer WSe_(2) in antiparallel interface stacking geometry,where local centrosymmetry of atomic registries at the twist interface does not favor the spontaneous electronic polarizations as recently observed in the parallel interface stacking geometry.The unconventional ferroelectric behaviors probed by electronic transport measurement occur at half filling insulating states at 1.5 K and gradually disappear at about 40 K.Single band Hubbard model based on the triangular moirélattice and the interlayer charge transfer controlled by insulating phase transition are proposed to interpret the formation of electronic polarization states near half filling in twisted WSe_(2) devices.Our work highlights the prominent role of many-body electronic interaction in fostering novel quantum states in moiré-structured systems.
