Boron hydrides release an abundant amount of hydrogen in the presence of a suitable catalyst.Accelerating bimolecular activation kinetics is the key to designing cost-effective catalysts for borohydride hydrolysis.In ...Boron hydrides release an abundant amount of hydrogen in the presence of a suitable catalyst.Accelerating bimolecular activation kinetics is the key to designing cost-effective catalysts for borohydride hydrolysis.In this study,the bimolecular activation of a polar O-Co-P site demonstrated superior hydrogen-generation kinetics(turnover frequency,TOF=37 min−1,298 K)and low activation energy(41.0 kJ mol^(−1))close to that of noble-metal-based catalysts.Through a combination of experiments and theoretical calculations,it was revealed that the activated dangling oxygen atom in the Co–O precursor effectively replaced via surface-phosphorization because of strong electronic interactions between the dangling oxygen and P atoms.This substitution modulated the local coordination environment and electronegativity around the surface Co sites and formed a new polar O-Co-P active site for optimizing the activation kinetics of ammonia borane and water.This strategy based on bimolecular activation may create new avenues in the field of catalysis.展开更多
Ammonia borane(AB) can be catalytically hydrolyzed to provide hydrogen at room temperature due to its high potentaial for hydrogen storage. Non-precious metal heterogeneous catalysts have broad application in the fiel...Ammonia borane(AB) can be catalytically hydrolyzed to provide hydrogen at room temperature due to its high potentaial for hydrogen storage. Non-precious metal heterogeneous catalysts have broad application in the field of energy catalysis. In this article, catalysts precursor is obtained from Co-Ti-resorcinol-formaldehyde resin by sol–gel method. Co/TiO_(2)@N-C(CTC) catalyst is prepared by calcining the precursor under high temperature conditions in nitrogen atmosphere. Co-CoO_x/TiO_(2)@N-C(COTC) is generated by the controllable oxidation reaction of CTC. The catalyst can effectively promote the release of hydrogen during the hydrolytic dehydrogenation of AB. High hydrogen generation at a specific rate of 5905 m L min^(-1) g_(Co)^(-1) is achieved at room temperature. The catalyst retains its 85% initial catalytic activity even for its fifth time use in AB hydrolysis. The synergistic effect among Co, Co_(3)O_(4) and TiO_(2) promotes the rate limiting step with dissociation and activation of water molecules by reducing its activation energy. The applied method in this study promotes the development of non-precious metals in catalysis for utilization in clean energy sources.展开更多
The design of high-performance catalysts is the key to the efficient utilization of hydrogen energy.In this work,a PdCu nanoalloy was successfully anchored on TiO_(2)encapsulated with carbon to construct a catalyst.Ou...The design of high-performance catalysts is the key to the efficient utilization of hydrogen energy.In this work,a PdCu nanoalloy was successfully anchored on TiO_(2)encapsulated with carbon to construct a catalyst.Outstanding kinetics of the hydrolysis of ammonia borane(turnover frequency of 279 mol·min^(-1·)mol_(Pd)^(-1))ranking the third place among Pd-based catalysts was achieved in the absence of alkali.Both experimental research and theoretical calculations reveal a lower activation energy of the B-H bond on the PdCu nanoalloy catalyst than that on pristine Pd and a lower activation energy of the O-H bond than that on pristine Cu.The redistribution of d electron and the shift of the d-band center play a critical role in increasing the electron density of Pd and improving the catalytic performances of Pd_(0.1)Cu_(0.9)/TiO_(2)-porous carbon(Pd_(0.1)Cu_(0.9)/T-PC).This work provides novel insights into highly dual-active alloys and sheds light on the mechanism of dual-active sites in promoting borohydride hydrolysis.展开更多
Acoustofluidic separation of cells and particles is an emerging technology that integrates acoustics and microfluidics.In the last decade,this technology has attracted significant attention due to its biocompatible,co...Acoustofluidic separation of cells and particles is an emerging technology that integrates acoustics and microfluidics.In the last decade,this technology has attracted significant attention due to its biocompatible,contactless,and labelfree nature.It has been widely validated in the separation of cells and submicron bioparticles and shows great potential in different biological and biomedical applications.This review first introduces the theories and mechanisms of acoustofluidic separation.Then,various applications of this technology in the separation of biological particles such as cells,viruses,biomolecules,and exosomes are summarized.Finally,we discuss the challenges and future prospects of this field.展开更多
Magnesium hydride(MgH_(2))is considered as an ideal hydrogen storage material with excellent hydrogen capacity,but the slow kinetics impedes its application.Herein,an efficient additive of V2C MXene-anchored PrF_(3) n...Magnesium hydride(MgH_(2))is considered as an ideal hydrogen storage material with excellent hydrogen capacity,but the slow kinetics impedes its application.Herein,an efficient additive of V2C MXene-anchored PrF_(3) nanoparticles(PrF_(3)/V_(2)C)was synthesized,which presents excellent catalytic effect in improving the reversibility and stability of hydrogen storage in MgH_(2).The initial dehydrogenation temperature of the 5 wt.% PrF_(3)/V_(2)C-containing MgH_(2)(182℃) is 105℃ lower than that of pure MgH_(2),and 6.5 wt.%hydrogen is rapidly released from 5 wt.%PrF_(3)/V_(2)C-added MgH_(2)sample in 6 min at 240℃.In addition,5 wt.%PrF_(3)/V_(2)C-containing MgH_(2) sample possesses outstanding reversible hydrogen storage capability of 6.5 wt.% after 10 cycles of dehydrogenation and hydrogenation.Microstructure analysis shows that the introduction of Pr improves the stability of V-species(V^(0)and V^(2+))and O-species(lattice oxygen(OL)and vacancy oxygen(OV))formed during ball milling,promotes the interaction between V-species and O-species,and enhances their reversibility,which contributes to the significant improvement in re/dehydrogenation reversibility and cycling stability of MgH_(2).This study provides effective ideas and strategies for the purpose of designing and fabricating high-efficient catalysts for solid-state hydrogen storage materials.展开更多
基金H.Z.and K.Z.contributed equally to this work.Financial supports from the National Natural Science Foundation of China (nos.22075254,52071135,51871090,U1804135,21805071,51671080,and 21401168)Plan for Scientific Inno-vation Talent of Henan Province (no.194200510019)Key Project of Educa-tional Commission of Henan Province (no.19A150025)are acknowledged.
文摘Boron hydrides release an abundant amount of hydrogen in the presence of a suitable catalyst.Accelerating bimolecular activation kinetics is the key to designing cost-effective catalysts for borohydride hydrolysis.In this study,the bimolecular activation of a polar O-Co-P site demonstrated superior hydrogen-generation kinetics(turnover frequency,TOF=37 min−1,298 K)and low activation energy(41.0 kJ mol^(−1))close to that of noble-metal-based catalysts.Through a combination of experiments and theoretical calculations,it was revealed that the activated dangling oxygen atom in the Co–O precursor effectively replaced via surface-phosphorization because of strong electronic interactions between the dangling oxygen and P atoms.This substitution modulated the local coordination environment and electronegativity around the surface Co sites and formed a new polar O-Co-P active site for optimizing the activation kinetics of ammonia borane and water.This strategy based on bimolecular activation may create new avenues in the field of catalysis.
基金Financial supports from the National Natural Science Foundation of China(No.51871090,U1804135,51671080,21401168 and 51471065)Plan for Scientific Innovation Talent of Henan Province(No.194200510019)are acknowledged.
文摘Ammonia borane(AB) can be catalytically hydrolyzed to provide hydrogen at room temperature due to its high potentaial for hydrogen storage. Non-precious metal heterogeneous catalysts have broad application in the field of energy catalysis. In this article, catalysts precursor is obtained from Co-Ti-resorcinol-formaldehyde resin by sol–gel method. Co/TiO_(2)@N-C(CTC) catalyst is prepared by calcining the precursor under high temperature conditions in nitrogen atmosphere. Co-CoO_x/TiO_(2)@N-C(COTC) is generated by the controllable oxidation reaction of CTC. The catalyst can effectively promote the release of hydrogen during the hydrolytic dehydrogenation of AB. High hydrogen generation at a specific rate of 5905 m L min^(-1) g_(Co)^(-1) is achieved at room temperature. The catalyst retains its 85% initial catalytic activity even for its fifth time use in AB hydrolysis. The synergistic effect among Co, Co_(3)O_(4) and TiO_(2) promotes the rate limiting step with dissociation and activation of water molecules by reducing its activation energy. The applied method in this study promotes the development of non-precious metals in catalysis for utilization in clean energy sources.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.22279118,22279117,52071135,51871090,and U1804135)the Fundamental Research Funds for the Universities of Henan Province(No.NSFRF220201).
文摘The design of high-performance catalysts is the key to the efficient utilization of hydrogen energy.In this work,a PdCu nanoalloy was successfully anchored on TiO_(2)encapsulated with carbon to construct a catalyst.Outstanding kinetics of the hydrolysis of ammonia borane(turnover frequency of 279 mol·min^(-1·)mol_(Pd)^(-1))ranking the third place among Pd-based catalysts was achieved in the absence of alkali.Both experimental research and theoretical calculations reveal a lower activation energy of the B-H bond on the PdCu nanoalloy catalyst than that on pristine Pd and a lower activation energy of the O-H bond than that on pristine Cu.The redistribution of d electron and the shift of the d-band center play a critical role in increasing the electron density of Pd and improving the catalytic performances of Pd_(0.1)Cu_(0.9)/TiO_(2)-porous carbon(Pd_(0.1)Cu_(0.9)/T-PC).This work provides novel insights into highly dual-active alloys and sheds light on the mechanism of dual-active sites in promoting borohydride hydrolysis.
基金the support from the National Natural Science Foundation of China(32101162,82127801)the Guangdong Basic and Applied Basic Research Foundation(2020A1515110088)the Shenzhen Science and Technology Innovation Commission(JCYJ20210324101401003).
文摘Acoustofluidic separation of cells and particles is an emerging technology that integrates acoustics and microfluidics.In the last decade,this technology has attracted significant attention due to its biocompatible,contactless,and labelfree nature.It has been widely validated in the separation of cells and submicron bioparticles and shows great potential in different biological and biomedical applications.This review first introduces the theories and mechanisms of acoustofluidic separation.Then,various applications of this technology in the separation of biological particles such as cells,viruses,biomolecules,and exosomes are summarized.Finally,we discuss the challenges and future prospects of this field.
基金supported by the National Natural Science Foundation of China(Nos.U22A20120,52071135,51871090,and U1804135)the Natural Science Foundation of Hebei Province for Innovation Groups Program(No.C2022203003)Fundamental Research Funds for the Universities of Henan Province(No.NSFRF220201).
文摘Magnesium hydride(MgH_(2))is considered as an ideal hydrogen storage material with excellent hydrogen capacity,but the slow kinetics impedes its application.Herein,an efficient additive of V2C MXene-anchored PrF_(3) nanoparticles(PrF_(3)/V_(2)C)was synthesized,which presents excellent catalytic effect in improving the reversibility and stability of hydrogen storage in MgH_(2).The initial dehydrogenation temperature of the 5 wt.% PrF_(3)/V_(2)C-containing MgH_(2)(182℃) is 105℃ lower than that of pure MgH_(2),and 6.5 wt.%hydrogen is rapidly released from 5 wt.%PrF_(3)/V_(2)C-added MgH_(2)sample in 6 min at 240℃.In addition,5 wt.%PrF_(3)/V_(2)C-containing MgH_(2) sample possesses outstanding reversible hydrogen storage capability of 6.5 wt.% after 10 cycles of dehydrogenation and hydrogenation.Microstructure analysis shows that the introduction of Pr improves the stability of V-species(V^(0)and V^(2+))and O-species(lattice oxygen(OL)and vacancy oxygen(OV))formed during ball milling,promotes the interaction between V-species and O-species,and enhances their reversibility,which contributes to the significant improvement in re/dehydrogenation reversibility and cycling stability of MgH_(2).This study provides effective ideas and strategies for the purpose of designing and fabricating high-efficient catalysts for solid-state hydrogen storage materials.