Reverse water-gas shift(RWGS) reaction-aided sustainable CO_(2) conversion has emerged as one promising and effective approach for simultaneously mitigating climate change and solidifying energy security.Molybdenum ca...Reverse water-gas shift(RWGS) reaction-aided sustainable CO_(2) conversion has emerged as one promising and effective approach for simultaneously mitigating climate change and solidifying energy security.Molybdenum carbide-based catalysts demonstrate excellent selectivity for sustainably transforming CO_(2) into CO product,but harsh carburization syntheses and insufficient catalytic activity and stability significantly hinder their related commercial applications.Herein,a facile "insideout" synthesis strategy was proposed to fabricate dispersed Cu clusters on sub-2 nm α-MoC nanoislands confined in pyridinic nitrogen-doped carbon(Cu-MoC/NC).This catalyst achieves the highest CO_(2) conversion rate of 2583.4 mmol_(CO_(2)) g_(cat)^(-1) h^(-1)compared to those of all reported Mo-based catalysts,and maintains excellent catalytic stability for 500 h under a low H_(2) partial pressure.Combined with X-ray absorption spectroscopy(XAS) and density functional theory(DFT) calculations,the electronegativity of pyridinic nitrogen intensifies the electron deficiency of α-MoC and strengthens the chemisorption of Cu clusters on α-MoC nanoislands surface,facilitating the electronic interaction and stability of Cu-MoC interface.This pyridinic nitrogenmodified Cu-MoC interface promotes the CO_(2) bridged adsorption at the interface and thus boosts C=O bond scissoring,inducing the transition of rate-limiting step and energy barrier reduction of the key intermediates.This interfacial engineering provides a sustainable and efficient strategy for improving both catalytic activity and stability of RWGS reaction to transform CO_(2) into value-added fuels and chemicals.展开更多
CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–deri...CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–derived N-rich mesoporous biochar(EPBC)supported atomic-level Cu-Mo_(2)C clusters(Cu-Mo_(2)C/EPBC).Unlike traditional acti-vated carbon(AC)supported Cu-Mo_(2)C particles(Cu-Mo_(2)C/AC),the Cu-Mo_(2)C/EPBC not only presents the better graphitization degree and larger specific surface area,but also uniformly andfirmly anchors atomic-level Cu-Mo_(2)C clusters due to the existence of pyridine nitrogen.Furthermore,the pyridine N of Cu-Mo_(2)C/EPBC strengthens an unblocked electron transfer between Mo_(2)C and Cu clusters,as verified by X-ray absorption spectroscopy.As a result,the synergistic effect between pyridinic N anchoring and the clusters interaction in Cu-Mo_(2)C/EPBC facilitates an improved CO selectivity of 99.95%at 500℃ compared with traditional Cu-Mo_(2)C/AC(99.60%),as well as about 3-fold CO_(2) conversion rate.Density functional theory calculations confirm that pyr-idine N-modified carbon activates the local electronic redistribution at Cu-Mo_(2)C clusters,which contributes to the decreased energy barrier of the transition state of CO^(*)+O^(*)+2H^(*),thereby triggering the transformation of rate-limited step during the redox pathway.This biomass-derived strategy opens perspective on producing sustain-able fuels and building blocks through the RWGS reaction.展开更多
Seeking for extremely active and durable bifunctional electrocatalysts towards the overall water splitting possesses a strategic significance on the development of sustainable and clean energy for the replacement of f...Seeking for extremely active and durable bifunctional electrocatalysts towards the overall water splitting possesses a strategic significance on the development of sustainable and clean energy for the replacement of fossil fuels.Ir-based nanomaterials are deemed as one of the most highefficiency oxygen evolution reaction electrocatalysts while the hydrogen evolution reaction performance is unfavorable.In this work,we report a one-pot hydrothermal synthesis of N-doped graphene anchored Ir nanoparticles(Ir/N-rGO) with ultrasmall particle size(~2.0 nm).Apart from the predictably superior OER performance,the resultant Ir/N-rGO also displays excellent hydrogen evolution reaction(HER) performance,requiring merely 76 and 260 mV overpotentials to achieve the current density of 10 mA cm^(-2) towards HER and OER,respectively.When applied as the bifunctional electrodes for overall water splitting,Ir/N-rGO needs a lower overpotential(1.74 V) to achieve a current density of50 mA cm^(-2) in alkaline solution,exceeding that of Pt/C and RuO_(2) couple(1.85 V).Thus,the as-fabricated Ir/N-rGO has a commendable prospect in the practical application of alkaline water electrocatalysis.展开更多
High conversion rate and selectivity are challenges for CO_(2)utilization through catalytic reverse water gas shift(RWGS)reaction.Herein,a novel mesoporous biochar(MB)supported Cu-Mo_(2)C nano-interface was prepared b...High conversion rate and selectivity are challenges for CO_(2)utilization through catalytic reverse water gas shift(RWGS)reaction.Herein,a novel mesoporous biochar(MB)supported Cu-Mo_(2)C nano-interface was prepared by consecutive physical activation of coconut shells followed by carbothermal hydrogen reduction of bimetal.As compared with traditional carbon materials,this MB exhibited ultra-high specific surface area(2693 m^(2)g^(−1))and mesopore volume of mesopore(0.81 cm^(3)g^(−1))with a narrow distribution(2-5 nm),responsible for the high dispersion of binary Cu-Mo_(2)C sites,CO_(2)adsorption and mass transfer in the reaction system.Moderate carbothermal reduction led to the sufficient reduction of Mo ion with carbon matrix of MB and dispersive growth of nano Cu-Mo_(2)C binary sites(~6.1 nm)on the surface of MB.Cu+species were formed from Cu0 via electron transfer and showed high dispersion with simultaneous boosted bimetal loading due to the strong interaction between nano Mo_(2)C and Cu.These were advantageous to the intrinsic activity and stability of the Cu-Mo_(2)C binary sites and their accessibility to the reactant molecules.Under the RWGS reaction conditions of 500℃,atmospheric pressure,and 300,000 ml/g/h gas hour space velocity,the CO_(2)conversion rate over Cu-Mo_(2)C/MB reached 27.74×10^(-5)molCO_(2)/gcat/s at very low H_(2)partial pres-sure,which was more than twice that over traditional carbon supported Cu-Mo_(2)C catalysts.In addition,this catalyst exhibited 99.08%CO selectivity and high stability for more than 50 h without a decrease in activity and selectivity.This study offers a new development strategy and a promising candidate for industrial RWGS.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:42377249,52476183National Key Research and Development Program of China,Grant/Award Number:2023YFD2201605。
文摘Reverse water-gas shift(RWGS) reaction-aided sustainable CO_(2) conversion has emerged as one promising and effective approach for simultaneously mitigating climate change and solidifying energy security.Molybdenum carbide-based catalysts demonstrate excellent selectivity for sustainably transforming CO_(2) into CO product,but harsh carburization syntheses and insufficient catalytic activity and stability significantly hinder their related commercial applications.Herein,a facile "insideout" synthesis strategy was proposed to fabricate dispersed Cu clusters on sub-2 nm α-MoC nanoislands confined in pyridinic nitrogen-doped carbon(Cu-MoC/NC).This catalyst achieves the highest CO_(2) conversion rate of 2583.4 mmol_(CO_(2)) g_(cat)^(-1) h^(-1)compared to those of all reported Mo-based catalysts,and maintains excellent catalytic stability for 500 h under a low H_(2) partial pressure.Combined with X-ray absorption spectroscopy(XAS) and density functional theory(DFT) calculations,the electronegativity of pyridinic nitrogen intensifies the electron deficiency of α-MoC and strengthens the chemisorption of Cu clusters on α-MoC nanoislands surface,facilitating the electronic interaction and stability of Cu-MoC interface.This pyridinic nitrogenmodified Cu-MoC interface promotes the CO_(2) bridged adsorption at the interface and thus boosts C=O bond scissoring,inducing the transition of rate-limiting step and energy barrier reduction of the key intermediates.This interfacial engineering provides a sustainable and efficient strategy for improving both catalytic activity and stability of RWGS reaction to transform CO_(2) into value-added fuels and chemicals.
基金support from National Natural Science Foundation of China(32101474 and 42377249)National Key Research and Development Program of China(2023YFD2201605).
文摘CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–derived N-rich mesoporous biochar(EPBC)supported atomic-level Cu-Mo_(2)C clusters(Cu-Mo_(2)C/EPBC).Unlike traditional acti-vated carbon(AC)supported Cu-Mo_(2)C particles(Cu-Mo_(2)C/AC),the Cu-Mo_(2)C/EPBC not only presents the better graphitization degree and larger specific surface area,but also uniformly andfirmly anchors atomic-level Cu-Mo_(2)C clusters due to the existence of pyridine nitrogen.Furthermore,the pyridine N of Cu-Mo_(2)C/EPBC strengthens an unblocked electron transfer between Mo_(2)C and Cu clusters,as verified by X-ray absorption spectroscopy.As a result,the synergistic effect between pyridinic N anchoring and the clusters interaction in Cu-Mo_(2)C/EPBC facilitates an improved CO selectivity of 99.95%at 500℃ compared with traditional Cu-Mo_(2)C/AC(99.60%),as well as about 3-fold CO_(2) conversion rate.Density functional theory calculations confirm that pyr-idine N-modified carbon activates the local electronic redistribution at Cu-Mo_(2)C clusters,which contributes to the decreased energy barrier of the transition state of CO^(*)+O^(*)+2H^(*),thereby triggering the transformation of rate-limited step during the redox pathway.This biomass-derived strategy opens perspective on producing sustain-able fuels and building blocks through the RWGS reaction.
基金financially supported by the National Natural Science Foundation of China (21875112)the Natural Science Foundation of Jiangsu Province (BK20171473)+1 种基金support from the National and Local Joint Engineering Research Center of Biomedical Functional Materialsa project sponsored by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Seeking for extremely active and durable bifunctional electrocatalysts towards the overall water splitting possesses a strategic significance on the development of sustainable and clean energy for the replacement of fossil fuels.Ir-based nanomaterials are deemed as one of the most highefficiency oxygen evolution reaction electrocatalysts while the hydrogen evolution reaction performance is unfavorable.In this work,we report a one-pot hydrothermal synthesis of N-doped graphene anchored Ir nanoparticles(Ir/N-rGO) with ultrasmall particle size(~2.0 nm).Apart from the predictably superior OER performance,the resultant Ir/N-rGO also displays excellent hydrogen evolution reaction(HER) performance,requiring merely 76 and 260 mV overpotentials to achieve the current density of 10 mA cm^(-2) towards HER and OER,respectively.When applied as the bifunctional electrodes for overall water splitting,Ir/N-rGO needs a lower overpotential(1.74 V) to achieve a current density of50 mA cm^(-2) in alkaline solution,exceeding that of Pt/C and RuO_(2) couple(1.85 V).Thus,the as-fabricated Ir/N-rGO has a commendable prospect in the practical application of alkaline water electrocatalysis.
基金National Natural Science Foundation of China(32101474,42377249)National Key Research and Development Program of China(2023YFD2201605).
文摘High conversion rate and selectivity are challenges for CO_(2)utilization through catalytic reverse water gas shift(RWGS)reaction.Herein,a novel mesoporous biochar(MB)supported Cu-Mo_(2)C nano-interface was prepared by consecutive physical activation of coconut shells followed by carbothermal hydrogen reduction of bimetal.As compared with traditional carbon materials,this MB exhibited ultra-high specific surface area(2693 m^(2)g^(−1))and mesopore volume of mesopore(0.81 cm^(3)g^(−1))with a narrow distribution(2-5 nm),responsible for the high dispersion of binary Cu-Mo_(2)C sites,CO_(2)adsorption and mass transfer in the reaction system.Moderate carbothermal reduction led to the sufficient reduction of Mo ion with carbon matrix of MB and dispersive growth of nano Cu-Mo_(2)C binary sites(~6.1 nm)on the surface of MB.Cu+species were formed from Cu0 via electron transfer and showed high dispersion with simultaneous boosted bimetal loading due to the strong interaction between nano Mo_(2)C and Cu.These were advantageous to the intrinsic activity and stability of the Cu-Mo_(2)C binary sites and their accessibility to the reactant molecules.Under the RWGS reaction conditions of 500℃,atmospheric pressure,and 300,000 ml/g/h gas hour space velocity,the CO_(2)conversion rate over Cu-Mo_(2)C/MB reached 27.74×10^(-5)molCO_(2)/gcat/s at very low H_(2)partial pres-sure,which was more than twice that over traditional carbon supported Cu-Mo_(2)C catalysts.In addition,this catalyst exhibited 99.08%CO selectivity and high stability for more than 50 h without a decrease in activity and selectivity.This study offers a new development strategy and a promising candidate for industrial RWGS.
