The two novel green oxidation processes of p/o-cresols to p/o-hydroxybenzaldehydes catalyzed by metalloporphyrins in the presence of molecular oxygen were developed in this work.Among the metalloporphyrins with differ...The two novel green oxidation processes of p/o-cresols to p/o-hydroxybenzaldehydes catalyzed by metalloporphyrins in the presence of molecular oxygen were developed in this work.Among the metalloporphyrins with different central ions and substituents studied,T(p-NO 2)PPCoCl and T(p-OCH 3)PPFeCl presented the highest activities for p-cresol and o-cresol oxidation reactions respectively.The molar ratio of sodium hydroxide to cresols and different reaction parameters including reaction temperature,reaction time and reaction pressure have been investigated,and 69.8%/50.4% conversions of p/o-cresol and 86.6%/26.6% selectivities for p/o-hydroxybenzaldehydes were reached under optimized conditions.展开更多
The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-co...The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-contained 6H-perovskites with a formula of Ba3LnIr2〇9(Ln=lanthanides)are investigated as oxygen evolution electrocatalysts,whose active subunits(i.e.,face-sharing Ir〇6 dimers)can be regulated by the lanthanides in terms of catalytic activity.By using density functional theory(DFT)calculations,we establish the theoretical trend in activity for Ba3LnIr2〇96H-perovskites,the activity of which is correlated with the difference of adsorption free energy(△G〇-△Goh)between O*and OH*reaction intermediates.We further establish a volcano curve between△Go—△Goh and the calculated 0 p-band center Among the Ba3LnIr2〇96H-perovskites,Ba3Lalr2〇9 locates at the peak of volcano curve,and correspondingly is the most active electrocatalyst due to the optimal 0 p-band property.展开更多
Anodic urea oxidation reaction(UOR)is an intriguing half reaction that can replace oxygen evolution reaction(OER)and work together with hydrogen evolution reaction(HER)toward simultaneous hydrogen fuel generation and ...Anodic urea oxidation reaction(UOR)is an intriguing half reaction that can replace oxygen evolution reaction(OER)and work together with hydrogen evolution reaction(HER)toward simultaneous hydrogen fuel generation and urea-rich wastewater purification;however,it remains a challenge to achieve overall urea electrolysis with high efficiency.Herein,we report a multifunctional electrocatalyst termed as Rh/Ni V-LDH,through integration of nickel-vanadium layered double hydroxide(LDH)with rhodium single-atom catalyst(SAC),to achieve this goal.The electrocatalyst delivers high HER mass activity of0.262 A mg^(-1) and exceptionally high turnover frequency(TOF)of 2.125 s^(-1) at an overpotential of100 m V.Moreover,exceptional activity toward urea oxidation is addressed,which requires a potential of 1.33 V to yield 10 mA cm^(-2),endorsing the potential to surmount the sluggish OER.The splendid catalytic activity is enabled by the synergy of the Ni V-LDH support and the atomically dispersed Rh sites(located on the Ni-V hollow sites)as evidenced both experimentally and theoretically.The selfsupported Rh/Ni V-LDH catalyst serving as the anode and cathode for overall urea electrolysis(1 mol L^(-1) KOH with 0.33 mol L^(-1) urea as electrolyte)only requires a small voltage of 1.47 V to deliver 100 mA cm^(-2) with excellent stability.This work provides important insights into multifunctional SAC design from the perspective of support sites toward overall electrolysis applications.展开更多
基金Supported by the Key Project of National Natural Science Foundation of China (21036009, 20776003)the Key Project of Natural Science Foundation of Beijing (2061001)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of the Beijing Municipality (PHR 200907105, PHR 201107104)
文摘The two novel green oxidation processes of p/o-cresols to p/o-hydroxybenzaldehydes catalyzed by metalloporphyrins in the presence of molecular oxygen were developed in this work.Among the metalloporphyrins with different central ions and substituents studied,T(p-NO 2)PPCoCl and T(p-OCH 3)PPFeCl presented the highest activities for p-cresol and o-cresol oxidation reactions respectively.The molar ratio of sodium hydroxide to cresols and different reaction parameters including reaction temperature,reaction time and reaction pressure have been investigated,and 69.8%/50.4% conversions of p/o-cresol and 86.6%/26.6% selectivities for p/o-hydroxybenzaldehydes were reached under optimized conditions.
文摘The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-contained 6H-perovskites with a formula of Ba3LnIr2〇9(Ln=lanthanides)are investigated as oxygen evolution electrocatalysts,whose active subunits(i.e.,face-sharing Ir〇6 dimers)can be regulated by the lanthanides in terms of catalytic activity.By using density functional theory(DFT)calculations,we establish the theoretical trend in activity for Ba3LnIr2〇96H-perovskites,the activity of which is correlated with the difference of adsorption free energy(△G〇-△Goh)between O*and OH*reaction intermediates.We further establish a volcano curve between△Go—△Goh and the calculated 0 p-band center Among the Ba3LnIr2〇96H-perovskites,Ba3Lalr2〇9 locates at the peak of volcano curve,and correspondingly is the most active electrocatalyst due to the optimal 0 p-band property.
基金finically supported by the National Key R&D Program of China(2017YFE0120500)the National Natural Science Foundation of China(51972129,51702150,and 21725102)+2 种基金the Key Research and Development Program of Hubei(2020BAB079)Bintuan Science and Technology Program(2020DB002,and 2022DB009)the Science and Technology Innovation Committee Foundation of Shenzhen(JCYJ20210324141613032 and JCYJ20190809142019365)。
文摘Anodic urea oxidation reaction(UOR)is an intriguing half reaction that can replace oxygen evolution reaction(OER)and work together with hydrogen evolution reaction(HER)toward simultaneous hydrogen fuel generation and urea-rich wastewater purification;however,it remains a challenge to achieve overall urea electrolysis with high efficiency.Herein,we report a multifunctional electrocatalyst termed as Rh/Ni V-LDH,through integration of nickel-vanadium layered double hydroxide(LDH)with rhodium single-atom catalyst(SAC),to achieve this goal.The electrocatalyst delivers high HER mass activity of0.262 A mg^(-1) and exceptionally high turnover frequency(TOF)of 2.125 s^(-1) at an overpotential of100 m V.Moreover,exceptional activity toward urea oxidation is addressed,which requires a potential of 1.33 V to yield 10 mA cm^(-2),endorsing the potential to surmount the sluggish OER.The splendid catalytic activity is enabled by the synergy of the Ni V-LDH support and the atomically dispersed Rh sites(located on the Ni-V hollow sites)as evidenced both experimentally and theoretically.The selfsupported Rh/Ni V-LDH catalyst serving as the anode and cathode for overall urea electrolysis(1 mol L^(-1) KOH with 0.33 mol L^(-1) urea as electrolyte)only requires a small voltage of 1.47 V to deliver 100 mA cm^(-2) with excellent stability.This work provides important insights into multifunctional SAC design from the perspective of support sites toward overall electrolysis applications.
