Zhengshan YangBowen DengKaifa DuHuayi Yin...
748-757页查看更多>>摘要：Molten carbonate is an excellent electrolyte for the electrochemical reduction of CO2 to carbonaceous materials.However,the electrolyte-electrode-reaction relationship has not been well understood.Herein,we propose a general descriptor,the CO2 activity,to reveal the electrolyte-electrode-reaction relationship by thermodynamic calculations and experimental studies.Experimental studies agree well with theoretical predictions that both cations(Li+,Ca2+,Sr2+and Ba2+)and anions(BO2,Ti5O148-,SiO32-)can modulate the CO2 activity to control both cathode and anode reactions in a typical molten carbonate electrolyzer in terms of tuning reaction products and overpotentials.In this regard,the reduction of CO32-can be interpreted as the direct reduction of CO2 generated from the dissociated CO32-,and the CO2 activity can be used as a general descriptor to predict the electrode reaction in molten carbonate.Overall,the CO2 activity descriptor unlocks the electrolyte-electrode-reaction relationship,thereby providing fundamental insights into guiding molten carbonate CO2 electrolysis.
Yang ZhouLice YuJinfa ChangLigang Feng...
758-770页查看更多>>摘要：Low carbon alcohol fuels electrolysis under ambient conditions is promising for green hydrogen generation instead of the traditional alcohol fuels steam reforming technique,and highly efficient bifunctional catalysts for membrane electrode fabrication are required to drive the electrolysis reactions.Herein,the efficient catalytic promotion effect of a novel catalyst promoter,CoTe.on Pt is demonstrated for low carbon alcohol fuels of methanol and ethanol electrolysis for hydrogen generation.Experimental and density functional theory calculation results indicate that the optimized electronic structure of Pt-CoTe/C resulting from the synergetic effect between Pt and CoTe further regulates the adsorption energies of CO and H*that enhances the catalytic ability for methanol and ethanol electrolysis.Moreover,the good water activation ability of CoTe and the strong electronic effect of Pt and CoTe increased the tolerance ability to the poisoning species as demonstrated by the CO-stripping technique.The high catalytic kinetics and stability,as well as the promotion effect,were also carefully discussed.Specifically,71.9％and 75.5％of the initial peak current density was maintained after 1000 CV cycles in acid electrolyte for methanol and ethanol oxidation;and a low overpotential of 30 and 35 mV was required to drive the hydrogen evolution reaction in methanol and ethanol solution at the current density of 10 mA cm-2.In the two-electrode system for alcohol fuels electrolysis,using the optimal Pt-CoTe/C catalyst as bi-functional catalysts,the cell potential of 0.66 V(0.67 V)was required to achieve 10 mA cm-2 for methanol(ethanol)electrolysis,much smaller than that of water electrolysis(1.76 V).The current study offers a novel platform for hydrogen generation via low carbon alcohol fuel electrolysis,and the result is helpful to the catalysis mechanism understanding of Pt assisted by the novel promoter.
Lu WangFeifei WangZhe DingYingxin Liu...
771-776页查看更多>>摘要：Aqueous zinc(Zn)batteries with Zn metal anodes are promising clean energy storage devices with intrinsic safety and low cost.However,Zn dendrite growth severely restricts the use of Zn anodes.To effectively suppress Zn dendrite growth,we propose a bilayer separator consisting of commercial butter paper and glass fiber membrane.The dense cellulose-based butter paper(BP)with low zincophilicity and high mechanical properties prevents the pore-filling behavior of deposited Zn and related separator piercing,effectively suppressing the Zn dendrite growth.As a result,the bilayer separators endow the Zn||Zn symmetrical batteries with a superlong cycling life of Zn anodes(over 5000 h)at 0.5 mA cm-2 and the full batteries enhanced capacity retention,demonstrating the advancement of the bilayer separator to afford excellent cyclability of aqueous metal batteries.
A.K.K.ViklaK.KoichumanovaSongbo HeK.Seshan...
777-788页查看更多>>摘要：Aqueous-phase reforming(APR)is an attractive process to produce bio-based hydrogen from waste biomass streams,during which the catalyst stability is often challenged due to the harsh reaction conditions.In this work,three Pt-based catalysts supported on C,AlO(OH),and ZrO2 were investigated for the APR of hydroxyacetone solution in a fixed bed reactor at 225 ℃ and 35 bar.Among them,the Pt/C catalyst showed the highest turnover frequency for H2 production(TOF of 8.9 molH2 molPt-1 min-1)and the longest catalyst stability.Over the AlO(OH)and ZrO2 supported Pt catalysts,the side reactions consuming H2,formation of coke,and Pt sintering result in a low H2 production and the fast catalyst deactivation.The proposed reaction pathways suggest that a promising APR catalyst should reform all oxygenates in the aqueous phase,minimize the hydrogenation of the oxygenates,maximize the WGS reaction,and inhibit the condensation and coking reactions for maximizing the hydrogen yield and a stable catalytic performance.
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