Electrocatalytic 5-hydroxymethylfurfural oxidation reaction(HMFOR)provides a promising strategy to convert biomass derivative to highvalue-added chemicals.Herein,a cascade strategy is proposed to construct Pd-NiCo_(2)...Electrocatalytic 5-hydroxymethylfurfural oxidation reaction(HMFOR)provides a promising strategy to convert biomass derivative to highvalue-added chemicals.Herein,a cascade strategy is proposed to construct Pd-NiCo_(2)O_(4)electrocatalyst by Pd loading on Ni-doped Co3O4 and for highly active and stable synergistic HMF oxidation.An elevated current density of 800 mA cm^(-2)can be achieved at 1.5 V,and both Faradaic efficiency and yield of 2,5-furandicarboxylic acid remained close to 100%over 10 consecutive electrolysis.Experimental and theoretical results unveil that the introduction of Pd atoms can modulate the local electronic structure of Ni/Co,which not only balances the competitive adsorption of HMF and OH-species,but also promote the active Ni^(3+)species formation,inducing high indirect oxidation activity.We have also discovered that Ni incorporation facilitates the Co2+pre-oxidation and electrophilic OH*generation to contribute direct oxidation process.This work provides a new approach to design advanced electrocatalyst for biomass upgrading.展开更多
Molybdenum carbide(MO_(2)C)materials are promising electrocatalysts with potential applications in hydrogen evolution reaction(HER)due to low cost and Pt-like electronic structures.Nevertheless,their HER activity is u...Molybdenum carbide(MO_(2)C)materials are promising electrocatalysts with potential applications in hydrogen evolution reaction(HER)due to low cost and Pt-like electronic structures.Nevertheless,their HER activity is usually hindered by the strong hydrogen binding energy.Moreover,the lack of water-cleaving site's makes it difficult for the catalysts to work in alkaline solutions.Here,we designed and synthesized a B and N dual-doped carbon layer that encapsulated on MO_(2)C nanocrystals(MO_(2)C@BNC)for accelerating HER under alkaline condition.The electronic interactions between the MO_(2)C nanocrystals and the multiple-doped carbon layer endow a near-zero H adsorption Gibbs free energy on the defective C atoms over the carbon shell.Meanwhile,the introduced B atoms afford optimal H_2O adsorption sites for the water-cleaving step.Accordingly,the dual-doped MO_(2)C catalyst with synergistic effect of non-metal sites delivers superior HER performances of a low overpotential(99 mV@10 mA cm^(-2))and a small Tafel slope(58.1 mV dec^(-1))in 1 M KOH solution.Furthermore,it presents a remarkable activity that outperforming the commercial 10%Pt/C catalyst at large current density,demonstrating its applicability in industrial water splitting.This study provides a reasonable design strategy towards noble-metal-free HER catalysts with high activity.展开更多
Accelerating beams have been the subject of extensive research in the last few decades because of their selfacceleration and diffraction-free propagation over several Rayleigh lengths.Here,we investigate the propagati...Accelerating beams have been the subject of extensive research in the last few decades because of their selfacceleration and diffraction-free propagation over several Rayleigh lengths.Here,we investigate the propagation dynamics of a Fresnel diffraction beam using the nonlocal nonlinear Schrodinger equation(NNLSE).When a nonlocal nonlinearity is introduced into the linear Schrodinger equation without invoking an external potential,the evolution behaviors of incident Fresnel diffraction beams are modulated regularly,and certain novel phenomena are observed.We show through numerical calculations,under varying degrees of nonlocality,that nonlocality significantly affects the evolution of Fresnel diffraction beams.Further,we briefly discuss the two-dimensional case as the equivalent of the product of two one-dimensional cases.At a critical point,the Airy-like intensity profile oscillates between the first and third quadrants,and the process repeats during propagation to yield an unusual oscillation.Our results are expected to contribute to the understanding of NNLSE and nonlinear optics.展开更多
基金financially supported by Key Research and Development Projects of Sichuan Province (2023YFG0222)“Tianfu Emei” Science and Technology Innovation Leader Program in Sichuan Province (2021)+3 种基金University of Electronic Science and Technology of China Talent Start-up Funds (A1098 5310 2360 1208)the Youth Innovation Promotion Association of CAS (2020458)National Natural Science Foundation of China (21464015, 21472235, 52122212, 12274391, 223210001)Beijing Natural Science Foundation (IS23045)
文摘Electrocatalytic 5-hydroxymethylfurfural oxidation reaction(HMFOR)provides a promising strategy to convert biomass derivative to highvalue-added chemicals.Herein,a cascade strategy is proposed to construct Pd-NiCo_(2)O_(4)electrocatalyst by Pd loading on Ni-doped Co3O4 and for highly active and stable synergistic HMF oxidation.An elevated current density of 800 mA cm^(-2)can be achieved at 1.5 V,and both Faradaic efficiency and yield of 2,5-furandicarboxylic acid remained close to 100%over 10 consecutive electrolysis.Experimental and theoretical results unveil that the introduction of Pd atoms can modulate the local electronic structure of Ni/Co,which not only balances the competitive adsorption of HMF and OH-species,but also promote the active Ni^(3+)species formation,inducing high indirect oxidation activity.We have also discovered that Ni incorporation facilitates the Co2+pre-oxidation and electrophilic OH*generation to contribute direct oxidation process.This work provides a new approach to design advanced electrocatalyst for biomass upgrading.
基金supported by the National Natural Science Foundation of China(Grant No.52202310)Natural Science Foundation of Jiangsu Province(Grant No.BK20191443)+7 种基金the Qinglan ProjectYouth Hundred Talents Programthe Toptalent Program of Yangzhou Universitythe Innovation technology platform project(YZ2020268)jointly built by Yangzhou City and Yangzhou UniversityPostgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX22_1703)the Key Research and Development Projects of Sichuan Province(23ZDYF0466)“Tianfu Emei”Science and Technology Innovation Leader Program in Sichuan ProvinceUniversity of Electronic Science and Technology of China Talent Start-up Funds(A1098531023601208)。
文摘Molybdenum carbide(MO_(2)C)materials are promising electrocatalysts with potential applications in hydrogen evolution reaction(HER)due to low cost and Pt-like electronic structures.Nevertheless,their HER activity is usually hindered by the strong hydrogen binding energy.Moreover,the lack of water-cleaving site's makes it difficult for the catalysts to work in alkaline solutions.Here,we designed and synthesized a B and N dual-doped carbon layer that encapsulated on MO_(2)C nanocrystals(MO_(2)C@BNC)for accelerating HER under alkaline condition.The electronic interactions between the MO_(2)C nanocrystals and the multiple-doped carbon layer endow a near-zero H adsorption Gibbs free energy on the defective C atoms over the carbon shell.Meanwhile,the introduced B atoms afford optimal H_2O adsorption sites for the water-cleaving step.Accordingly,the dual-doped MO_(2)C catalyst with synergistic effect of non-metal sites delivers superior HER performances of a low overpotential(99 mV@10 mA cm^(-2))and a small Tafel slope(58.1 mV dec^(-1))in 1 M KOH solution.Furthermore,it presents a remarkable activity that outperforming the commercial 10%Pt/C catalyst at large current density,demonstrating its applicability in industrial water splitting.This study provides a reasonable design strategy towards noble-metal-free HER catalysts with high activity.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61805068,61875053,and 62074127)China Postdoctoral Science Foundation(Grant No.2017M620300)the Fund from the Science and Technology Department of Henan Province,China(Grant No.202102210111).
文摘Accelerating beams have been the subject of extensive research in the last few decades because of their selfacceleration and diffraction-free propagation over several Rayleigh lengths.Here,we investigate the propagation dynamics of a Fresnel diffraction beam using the nonlocal nonlinear Schrodinger equation(NNLSE).When a nonlocal nonlinearity is introduced into the linear Schrodinger equation without invoking an external potential,the evolution behaviors of incident Fresnel diffraction beams are modulated regularly,and certain novel phenomena are observed.We show through numerical calculations,under varying degrees of nonlocality,that nonlocality significantly affects the evolution of Fresnel diffraction beams.Further,we briefly discuss the two-dimensional case as the equivalent of the product of two one-dimensional cases.At a critical point,the Airy-like intensity profile oscillates between the first and third quadrants,and the process repeats during propagation to yield an unusual oscillation.Our results are expected to contribute to the understanding of NNLSE and nonlinear optics.
