Structural reconstruction of electrocatalysts plays a pivotal role in catalytic performances for CO_(2)reduction reaction(CO_(2)RR),whereas the behavior is by far superficially understood.Here,we report that CO_(2)acc...Structural reconstruction of electrocatalysts plays a pivotal role in catalytic performances for CO_(2)reduction reaction(CO_(2)RR),whereas the behavior is by far superficially understood.Here,we report that CO_(2)accessibility results in a universal self-adaptive structural reconstruction from Cu_(2)O to Cu@CuxO composites,ending with feeding gas-dependent microstructures and catalytic performances.The CO_(2)-rich atmosphere favors reconstruction for CO_(2)RR,whereas the CO_(2)-deficient one prefers that for hydrogen evolution reaction.With the assistance of spectroscopic analysis and theoretical calculations,we uncover a CO_(2)-induced passivation behavior by identifying a reductionresistant but catalytic active Cu(I)-rich amorphous layer stabilized by*CO intermediates.Additionally,we find extra CO production is indispensable for the robust production of C2H4.An inverse correlation between durability and FECO/FEC2H4 is disclosed,suggesting that the selfstabilization process involving the absorption of*CO intermediates on Cu(I)sites is essential for durable electrolysis.Guided by this insight,we design hollow Cu_(2)O nanospheres for durable and selective CO_(2)RR electrolysis in producing C2H4.Our work recognizes the previously overlooked passivation reconstruction and self-stabilizing behavior and highlights the critical role of the local atmosphere in modulating reconstruction and catalytic processes.展开更多
Emerging as a new class of two-dimensional materials with atomically thin layers,MBenes have great potential for many important applications such as energy storage and electrocatalysis.Toward mitigating carbon footpri...Emerging as a new class of two-dimensional materials with atomically thin layers,MBenes have great potential for many important applications such as energy storage and electrocatalysis.Toward mitigating carbon footprint,there has been increasing interest in CO_(2)/CO conversion on MBenes,but mostly focused on C_(1) products.C^(2+) chemicals generally possess higher energy densities and wider applications than C_(1) counterparts.However,C–C coupling is technically challenging because of high energy requirement and currently few catalysts are suited for this process.Here,we explore electrochemical CO reduction reaction to C_(2) chemicals on Mo_(2)B_(2)O_(2) MBene via density-functional theory calculations.Remarkably,the most favorable CO–COH coupling is revealed to be a spontaneous and barrierless process,making Mo_(2)B_(2)O_(2) an efficient catalyst for C–C coupling.Among C_(1) and C_(2) chemicals,ethanol is predicted to be the primary product.Furthermore,by charge and bond analysis,it is unraveled that there exist significantly more unbonded electrons in the C atom of intermediate*COH than other C_(1) intermediates,which is responsible for the facile C–C coupling.From an atomic scale,this work provides microscopic insight into C–C coupling process and suggests Mo_(2)B_(2)O_(2) a promising catalyst for electrochemical CO reduction to C_(2) chemicals.展开更多
A new method based on phononic crystals is presented to detect the concentration of heavy water(D_(2)O)in an H_(2)O-D_(2)O mixture.Results have been obtained and analyzed in the concentration range of 0%-10%and 90%-10...A new method based on phononic crystals is presented to detect the concentration of heavy water(D_(2)O)in an H_(2)O-D_(2)O mixture.Results have been obtained and analyzed in the concentration range of 0%-10%and 90%-100%D_(2)O.A proposed structure of tungsten scatterers in an aluminum host is studied.In order to detect the target material,a cavity region is considered as a sound wave resonator in which the target material with different concentrations of D_(2)O is embedded.By changing the concentration of D_(2)O in the H_(2)O-D_(2)O mixture,the resonance frequency undergoes a frequency shift.Each 1%change in D_(2)O concentration in the H_(2)O-D_(2)O mixture causes a frequency change of about 120 Hz.The finite element method is used as the numerical method to calculate and analyze the natural frequencies and transmission spectra of the proposed sensor.The performance evaluation index shows a high Q factor up to 1475758 and a high sensitivity up to 13075,which are acceptable values for sensing purposes.The other figures of merit related to the detection performance also indicate high-quality performance of the designed sensor.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.22479097)the Shanghai Science and Technology Committee(Grant No.23ZR1433000)the National High-Level Talent Program for Young Scholars,the Start-up Fund(F.S.)from Shanghai Jiao Tong University.
文摘Structural reconstruction of electrocatalysts plays a pivotal role in catalytic performances for CO_(2)reduction reaction(CO_(2)RR),whereas the behavior is by far superficially understood.Here,we report that CO_(2)accessibility results in a universal self-adaptive structural reconstruction from Cu_(2)O to Cu@CuxO composites,ending with feeding gas-dependent microstructures and catalytic performances.The CO_(2)-rich atmosphere favors reconstruction for CO_(2)RR,whereas the CO_(2)-deficient one prefers that for hydrogen evolution reaction.With the assistance of spectroscopic analysis and theoretical calculations,we uncover a CO_(2)-induced passivation behavior by identifying a reductionresistant but catalytic active Cu(I)-rich amorphous layer stabilized by*CO intermediates.Additionally,we find extra CO production is indispensable for the robust production of C2H4.An inverse correlation between durability and FECO/FEC2H4 is disclosed,suggesting that the selfstabilization process involving the absorption of*CO intermediates on Cu(I)sites is essential for durable electrolysis.Guided by this insight,we design hollow Cu_(2)O nanospheres for durable and selective CO_(2)RR electrolysis in producing C2H4.Our work recognizes the previously overlooked passivation reconstruction and self-stabilizing behavior and highlights the critical role of the local atmosphere in modulating reconstruction and catalytic processes.
基金the A*STAR LCER-FI project(LCERFI01-0033 U2102d2006)the Ministry of Education of Singapore and the National University of Singapore(C-261-000-207-532/C-261-000-777-532 and R-279-000-574-114)for financial support.
文摘Emerging as a new class of two-dimensional materials with atomically thin layers,MBenes have great potential for many important applications such as energy storage and electrocatalysis.Toward mitigating carbon footprint,there has been increasing interest in CO_(2)/CO conversion on MBenes,but mostly focused on C_(1) products.C^(2+) chemicals generally possess higher energy densities and wider applications than C_(1) counterparts.However,C–C coupling is technically challenging because of high energy requirement and currently few catalysts are suited for this process.Here,we explore electrochemical CO reduction reaction to C_(2) chemicals on Mo_(2)B_(2)O_(2) MBene via density-functional theory calculations.Remarkably,the most favorable CO–COH coupling is revealed to be a spontaneous and barrierless process,making Mo_(2)B_(2)O_(2) an efficient catalyst for C–C coupling.Among C_(1) and C_(2) chemicals,ethanol is predicted to be the primary product.Furthermore,by charge and bond analysis,it is unraveled that there exist significantly more unbonded electrons in the C atom of intermediate*COH than other C_(1) intermediates,which is responsible for the facile C–C coupling.From an atomic scale,this work provides microscopic insight into C–C coupling process and suggests Mo_(2)B_(2)O_(2) a promising catalyst for electrochemical CO reduction to C_(2) chemicals.
文摘A new method based on phononic crystals is presented to detect the concentration of heavy water(D_(2)O)in an H_(2)O-D_(2)O mixture.Results have been obtained and analyzed in the concentration range of 0%-10%and 90%-100%D_(2)O.A proposed structure of tungsten scatterers in an aluminum host is studied.In order to detect the target material,a cavity region is considered as a sound wave resonator in which the target material with different concentrations of D_(2)O is embedded.By changing the concentration of D_(2)O in the H_(2)O-D_(2)O mixture,the resonance frequency undergoes a frequency shift.Each 1%change in D_(2)O concentration in the H_(2)O-D_(2)O mixture causes a frequency change of about 120 Hz.The finite element method is used as the numerical method to calculate and analyze the natural frequencies and transmission spectra of the proposed sensor.The performance evaluation index shows a high Q factor up to 1475758 and a high sensitivity up to 13075,which are acceptable values for sensing purposes.The other figures of merit related to the detection performance also indicate high-quality performance of the designed sensor.
基金This work is supported by the National Natural Science Foundation of China(No.22103075,No.21827804,and No.22173089)the National Key R&D Program of China(No.2021YFA0716801andNo.2017YFA0303502).
