CO oxidation has been performed on Co_(3)O_(4) nanobelts and nanocubes as model catalysts.The Co_(3)O_(4) nanobelts which have a predominance of exposed{011}planes are more active than Co_(3)O_(4) nanocubes with expos...CO oxidation has been performed on Co_(3)O_(4) nanobelts and nanocubes as model catalysts.The Co_(3)O_(4) nanobelts which have a predominance of exposed{011}planes are more active than Co_(3)O_(4) nanocubes with exposed{001}planes.Temperature programmed reduction of CO shows that Co_(3)O_(4) nanobelts have stronger reducing properties than Co_(3)O_(4) nanocubes.The essence of shape and crystal plane effect is revealed by the fact that turnover frequency of Co3+sites of{011}planes on Co_(3)O_(4) nanobelts is far higher than that of{001}planes on Co_(3)O_(4) nanocubes.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
Proton exchange membrane fuel cells(PEMFCs)suffer extreme CO poisoning even at PPM level(<10 ppm),owning to the preferential CO adsorption and the consequential blockage of the catalyst surface.Herein,however,we re...Proton exchange membrane fuel cells(PEMFCs)suffer extreme CO poisoning even at PPM level(<10 ppm),owning to the preferential CO adsorption and the consequential blockage of the catalyst surface.Herein,however,we report that CO itself can become an easily convertible fuel in PEMFC using atomically dispersed Rh catalysts(Rh-N-C).With CO to CO_(2) conversion initiates at 0 V,pure CO powered fuel cell attains unprecedented power density at 236 mW cm^(-2),with maximum CO turnover frequency(64.65 s^(-1),363 K)far exceeding any chemical or electrochemical catalysts reported.Moreover,this feature enables efficient CO selective removal from H_(2) gas stream through the PEMFC technique,with CO concentration reduced by one order of magnitude through running only one single cell,while simultaneously harvesting electricity.We attribute such catalytic behavior to the weak CO adsorption and the co-activation of H_(2)O due to the interplay between two adjacent Rh sites.展开更多
In the purification process of automobile exhaust,existing water plays an important role as an oxidant,which converts CO and hydrocarbons（HCs） by the water-gas shift（WGS） and the steam reforming（SR） reactions,re...In the purification process of automobile exhaust,existing water plays an important role as an oxidant,which converts CO and hydrocarbons（HCs） by the water-gas shift（WGS） and the steam reforming（SR） reactions,respectively,especially at high temperatures.Meanwhile it is major component of the exhaust which can affect significantly the thermal stability of the three-way catalyst.Activity experiments were carried out close to the real operation conditions（GHSV,concentration,etc.） with a Pd/Ce0.67Zr0.33O2 catalyst supplying information on the CO and C3H8 oxidation reactions in feedstream formed by different reactant combinations.The obtained results showed that the activity of the CO and C3H8 oxidation was promoted by the addition of steam due to the WGS and SR reactions.The WGS and SR reaction were competitive under oxygen-lean conditions.The kinetic analysis was considered for WGS and SR reactions.展开更多
To investigate the effect purification plays on nanoparticle (NP) synthesis and catalytic activity, three copies of Pd4 (TSNAVHPTLRHL) fused to the N-terminus of Green Fluorescent Protein (GFP) was produced recombinan...To investigate the effect purification plays on nanoparticle (NP) synthesis and catalytic activity, three copies of Pd4 (TSNAVHPTLRHL) fused to the N-terminus of Green Fluorescent Protein (GFP) was produced recombinantly and its characteristics pre and post purification was assessed. An E. coli expression system was employed, and purification was performed with Immobilized Metal Affinity Column (IMAC). Transmission electron microscopy (TEM) was utilized to examine the morphology of NPs synthesized with an enriched protein sample and ImageJ was used to determine the average size to be 2.44 nm. The turnover frequency of fabricated NP from the purified protein was analyzed by a model Suzuki-Miyaura coupling reactions and determined to be 33,000 hr<sup>-1</sup>. This value is three times higher than the turnover frequency when crude lysate containing (Pd4)<sub>3</sub>-GFP was used during NP synthesis. This result shows that enrichment enhanced the catalytic activity of NP.展开更多
A series of Pd catalysts supported on commercial Ce-Zr solid solution（Pd/CZ） calcined at different tem- peratures（750, 900 and 1050 %℃） was prepared via an incipient wetness impregnation method. The activities of...A series of Pd catalysts supported on commercial Ce-Zr solid solution（Pd/CZ） calcined at different tem- peratures（750, 900 and 1050 %℃） was prepared via an incipient wetness impregnation method. The activities of the fresh and hydrothermally aged PdTCZ catalysts were tested for total oxidation of CO and C3H8. For CO oxidation, the activity of either fresh or aged Pd/CZ catalysts decreased with the elevating of calcination temperature of CZ support, with a fresh catalyst calcined at 750 ℃ possessing the highest activity and hydrothermal stability. For C3H8 total oxidation, the activity of Pd/CZ catalysts could be improved by increasing the calcination temperature of support. However, the aged Pd/CZ catalysts showed higher activity than corresponding fresh Pd/CZ catalysts. The turnover frequency（TOF） over Pd/CZ catalyst for CO oxidation increased with increasing reduction ability of the catalysts, with a fresh catalyst calcined at 750 ℃ having the highest value（0.27 s^-1）. However, the TOF of Pd/CZ catalyst for C3Hs total oxidation was mainly affected by the size of Pd particles, and large Pd particles possessed a higher activity, with the highest TOF value（0.96s^-1） obtained over an aged catalyst calcined at 1050 ℃.展开更多
K＋-doped Bi0.02Co was investigated as catalyst for N2O decomposition. It was found that the catalytic performance of the Bi0.02Co catalyst, which was prepared by coprecipitation method, can be effectively modified by...K＋-doped Bi0.02Co was investigated as catalyst for N2O decomposition. It was found that the catalytic performance of the Bi0.02Co catalyst, which was prepared by coprecipitation method, can be effectively modified by potassium cations via impregnation. The optimized K0.01Bi0.02Co catalyst exhibited much higher activity compared with Bi0.02Co and K0.01Co for the reaction in feed gas 0.2% N2O/Ar, irrespective of the presence or absence of impurity gas（volume fraction） 5%02, 2%H20, 0.12%NO and 10%CO2. Characterization of the catalysts with H2 temperature programmed reduction（H2-TPR） and O2 temperature programmed desorption（O2-TPD） indicate that the Co--O bond in Bi0.02Co was weakened by the K＋ doping, and hence the K0.01Bi0.02Co catalyst has much higher turnover frequency（TOF） than CO3O4 spinel and Bi0.02Co for the reaction.展开更多
基金This work was supported by National Natural Science Foundation of China(NSFC)(Nos.10979031,20921001,and 90606006)the“973”State Key Project(No.2006CB932303)and the China Postdoctoral Science Foundation(No.20080440361).
文摘CO oxidation has been performed on Co_(3)O_(4) nanobelts and nanocubes as model catalysts.The Co_(3)O_(4) nanobelts which have a predominance of exposed{011}planes are more active than Co_(3)O_(4) nanocubes with exposed{001}planes.Temperature programmed reduction of CO shows that Co_(3)O_(4) nanobelts have stronger reducing properties than Co_(3)O_(4) nanocubes.The essence of shape and crystal plane effect is revealed by the fact that turnover frequency of Co3+sites of{011}planes on Co_(3)O_(4) nanobelts is far higher than that of{001}planes on Co_(3)O_(4) nanocubes.
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.
基金supported by the National Key Research and Development Program of China (2017YFB0102900)the National Natural Science Foundation of China (21875243, 21633008, 21673221, and U1601211)+3 种基金Jilin Provincial Science and Technology Development Program (20200201001JC, 20190201270JC, and 20180101030JC)supported by the High Performance Computing Center of Jilin University and Jilin ProvinceNetwork and Computing Center of Changchun Institute of Applied Chemistry, Chinese Academy of Sciencessupported by Linglu Instruments (Shanghai) Co., Ltd.
文摘Proton exchange membrane fuel cells(PEMFCs)suffer extreme CO poisoning even at PPM level(<10 ppm),owning to the preferential CO adsorption and the consequential blockage of the catalyst surface.Herein,however,we report that CO itself can become an easily convertible fuel in PEMFC using atomically dispersed Rh catalysts(Rh-N-C).With CO to CO_(2) conversion initiates at 0 V,pure CO powered fuel cell attains unprecedented power density at 236 mW cm^(-2),with maximum CO turnover frequency(64.65 s^(-1),363 K)far exceeding any chemical or electrochemical catalysts reported.Moreover,this feature enables efficient CO selective removal from H_(2) gas stream through the PEMFC technique,with CO concentration reduced by one order of magnitude through running only one single cell,while simultaneously harvesting electricity.We attribute such catalytic behavior to the weak CO adsorption and the co-activation of H_(2)O due to the interplay between two adjacent Rh sites.
基金supported by the National High-Tech Research and Development Program of China(2009AA064803)
文摘In the purification process of automobile exhaust,existing water plays an important role as an oxidant,which converts CO and hydrocarbons（HCs） by the water-gas shift（WGS） and the steam reforming（SR） reactions,respectively,especially at high temperatures.Meanwhile it is major component of the exhaust which can affect significantly the thermal stability of the three-way catalyst.Activity experiments were carried out close to the real operation conditions（GHSV,concentration,etc.） with a Pd/Ce0.67Zr0.33O2 catalyst supplying information on the CO and C3H8 oxidation reactions in feedstream formed by different reactant combinations.The obtained results showed that the activity of the CO and C3H8 oxidation was promoted by the addition of steam due to the WGS and SR reactions.The WGS and SR reaction were competitive under oxygen-lean conditions.The kinetic analysis was considered for WGS and SR reactions.
文摘To investigate the effect purification plays on nanoparticle (NP) synthesis and catalytic activity, three copies of Pd4 (TSNAVHPTLRHL) fused to the N-terminus of Green Fluorescent Protein (GFP) was produced recombinantly and its characteristics pre and post purification was assessed. An E. coli expression system was employed, and purification was performed with Immobilized Metal Affinity Column (IMAC). Transmission electron microscopy (TEM) was utilized to examine the morphology of NPs synthesized with an enriched protein sample and ImageJ was used to determine the average size to be 2.44 nm. The turnover frequency of fabricated NP from the purified protein was analyzed by a model Suzuki-Miyaura coupling reactions and determined to be 33,000 hr<sup>-1</sup>. This value is three times higher than the turnover frequency when crude lysate containing (Pd4)<sub>3</sub>-GFP was used during NP synthesis. This result shows that enrichment enhanced the catalytic activity of NP.
基金Technology Support Program of China(2007BAE08B02)Fujian Province Education Department Science and Technology project(JK2011005)+1 种基金Natural Science Foundation of Fujian Province(2013J01038)PetroChina Innovation Foundation(2013D-5006-0506)
文摘A series of Pd catalysts supported on commercial Ce-Zr solid solution（Pd/CZ） calcined at different tem- peratures（750, 900 and 1050 %℃） was prepared via an incipient wetness impregnation method. The activities of the fresh and hydrothermally aged PdTCZ catalysts were tested for total oxidation of CO and C3H8. For CO oxidation, the activity of either fresh or aged Pd/CZ catalysts decreased with the elevating of calcination temperature of CZ support, with a fresh catalyst calcined at 750 ℃ possessing the highest activity and hydrothermal stability. For C3H8 total oxidation, the activity of Pd/CZ catalysts could be improved by increasing the calcination temperature of support. However, the aged Pd/CZ catalysts showed higher activity than corresponding fresh Pd/CZ catalysts. The turnover frequency（TOF） over Pd/CZ catalyst for CO oxidation increased with increasing reduction ability of the catalysts, with a fresh catalyst calcined at 750 ℃ having the highest value（0.27 s^-1）. However, the TOF of Pd/CZ catalyst for C3Hs total oxidation was mainly affected by the size of Pd particles, and large Pd particles possessed a higher activity, with the highest TOF value（0.96s^-1） obtained over an aged catalyst calcined at 1050 ℃.
基金Supported by the State Hi-tech Research and Development Project of the Ministry of Science and Technology of China（No. 2013AA030705） and the National Natural Science Foundation of China（Nos. 21177016, 21277019）.
文摘K＋-doped Bi0.02Co was investigated as catalyst for N2O decomposition. It was found that the catalytic performance of the Bi0.02Co catalyst, which was prepared by coprecipitation method, can be effectively modified by potassium cations via impregnation. The optimized K0.01Bi0.02Co catalyst exhibited much higher activity compared with Bi0.02Co and K0.01Co for the reaction in feed gas 0.2% N2O/Ar, irrespective of the presence or absence of impurity gas（volume fraction） 5%02, 2%H20, 0.12%NO and 10%CO2. Characterization of the catalysts with H2 temperature programmed reduction（H2-TPR） and O2 temperature programmed desorption（O2-TPD） indicate that the Co--O bond in Bi0.02Co was weakened by the K＋ doping, and hence the K0.01Bi0.02Co catalyst has much higher turnover frequency（TOF） than CO3O4 spinel and Bi0.02Co for the reaction.
