The reactant concentration at the catalytic interface holds the key to the activity of electrocatalytic hydrogen evolution reaction(HER),mainly referring to the capacity of adsorbing hydrogen and electron accessibilit...The reactant concentration at the catalytic interface holds the key to the activity of electrocatalytic hydrogen evolution reaction(HER),mainly referring to the capacity of adsorbing hydrogen and electron accessibility.With hydrogen adsorption free energy(ΔGH)as a reactivity descriptor,the volcano curve based on Sabatier principle is established to evaluate the hydrogen evolution activity of catalysts.However,the role of electron as reactant received insufficient attention,especially for noble metal-free compound catalysts with poor conductivity,leading to cognitive gap between electronic conductivity and apparent catalytic activity.Herein we successfully construct a series of catalyst models with gradient conductivities by regulating molybdenum disulfide(MoS_(2))electronic bandgap via a simple solvothermal method.We demonstrate that the conductivity of catalysts greatly affects the overall catalytic activity.We further elucidate the key role of intrinsic conductivity of catalyst towards water electrolysis,mainly concentrating on the electron transport from electrode to catalyst,the electron accumulation process at the catalyst layer,and the charge transfer progress from catalyst to reactant.Theoretical and experimental evidence demonstrates that,with the enhancement in electron accessibility at the catalytic interface,the dominant parameter governing overall HER activity gradually converts from electron accessibility to combination of electron accessibility and hydrogen adsorbing energy.Our results provide the insight from various perspective for developing noble metal-free catalysts in electrocatalysis beyond HER.展开更多
Designing feasible electrocatalysts towards oxygen reduction reaction(ORR)requires advancement in both activity and stability,where attaining high stability is of extreme importance as the catalysts are expected to wo...Designing feasible electrocatalysts towards oxygen reduction reaction(ORR)requires advancement in both activity and stability,where attaining high stability is of extreme importance as the catalysts are expected to work efficiently under frequent start-up/shut down circumstances for at least several thousand hours.Alloying platinum with early transition metals(i.e.,Pt–La alloy)is revealed as efficient catalysts construction strategy to potentially satisfy these demands.Here we report a Pt5La intermetallic compound synthesized by a novel and facile strategy.Due to the strong electronic interactions between Pt and La,the resultant Pt5La alloy catalyst exhibits enhanced activity with half wave of 0.92 V and mass activity of 0.49 A·mgPt^(−1),which strictly follows the 4e transfer pathway.More importantly,the catalyst performs superior stability during 30,000 cycles of accelerated stressed test(AST)with mass activity retention of 93.9%.This study provides new opportunities for future applications of Pt-rare earth metal alloy with excellent electrocatalytic properties.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA21090400)the Instrument Developing Project of the Chinese Academy of Sciencesthe Jilin Province Science and Technology Development Program(Nos.20210301008GX,20200201001JC,and 20210502002ZP).
文摘The reactant concentration at the catalytic interface holds the key to the activity of electrocatalytic hydrogen evolution reaction(HER),mainly referring to the capacity of adsorbing hydrogen and electron accessibility.With hydrogen adsorption free energy(ΔGH)as a reactivity descriptor,the volcano curve based on Sabatier principle is established to evaluate the hydrogen evolution activity of catalysts.However,the role of electron as reactant received insufficient attention,especially for noble metal-free compound catalysts with poor conductivity,leading to cognitive gap between electronic conductivity and apparent catalytic activity.Herein we successfully construct a series of catalyst models with gradient conductivities by regulating molybdenum disulfide(MoS_(2))electronic bandgap via a simple solvothermal method.We demonstrate that the conductivity of catalysts greatly affects the overall catalytic activity.We further elucidate the key role of intrinsic conductivity of catalyst towards water electrolysis,mainly concentrating on the electron transport from electrode to catalyst,the electron accumulation process at the catalyst layer,and the charge transfer progress from catalyst to reactant.Theoretical and experimental evidence demonstrates that,with the enhancement in electron accessibility at the catalytic interface,the dominant parameter governing overall HER activity gradually converts from electron accessibility to combination of electron accessibility and hydrogen adsorbing energy.Our results provide the insight from various perspective for developing noble metal-free catalysts in electrocatalysis beyond HER.
基金supported by National Key R&D Program of China(No.2021YFA1501101)the National Natural Science Foundation of China(Nos.21875243,21673220,21733004,and U1601211)+1 种基金the Jilin Province Science and Technology Development Program(Nos.20190201270JC,20180101030JC,and 20200201001JC)Dalian National Laboratory for Clean Energy(DNL),Chinese Academy of Sciences(CAS),and the Research Innovation Fund(No.DNL202010).
文摘Designing feasible electrocatalysts towards oxygen reduction reaction(ORR)requires advancement in both activity and stability,where attaining high stability is of extreme importance as the catalysts are expected to work efficiently under frequent start-up/shut down circumstances for at least several thousand hours.Alloying platinum with early transition metals(i.e.,Pt–La alloy)is revealed as efficient catalysts construction strategy to potentially satisfy these demands.Here we report a Pt5La intermetallic compound synthesized by a novel and facile strategy.Due to the strong electronic interactions between Pt and La,the resultant Pt5La alloy catalyst exhibits enhanced activity with half wave of 0.92 V and mass activity of 0.49 A·mgPt^(−1),which strictly follows the 4e transfer pathway.More importantly,the catalyst performs superior stability during 30,000 cycles of accelerated stressed test(AST)with mass activity retention of 93.9%.This study provides new opportunities for future applications of Pt-rare earth metal alloy with excellent electrocatalytic properties.
