为寻求一种较好的Pt-Co/C纳米合金催化剂合成方法,运用浸渍还原法制备两种Pt-Co/C催化剂,运用循环伏安和线性扫描的方法测试它们在H_(2)SO_(4)溶液中有无CH3OH时,对O_(2)的电催化还原情况及抗甲醇性能,同时与商用Pt/C催化剂进行还原性...为寻求一种较好的Pt-Co/C纳米合金催化剂合成方法,运用浸渍还原法制备两种Pt-Co/C催化剂,运用循环伏安和线性扫描的方法测试它们在H_(2)SO_(4)溶液中有无CH3OH时,对O_(2)的电催化还原情况及抗甲醇性能,同时与商用Pt/C催化剂进行还原性能比较。结果表明:与商用Pt/C催化剂电极相比,Pt-Co/C(1)催化剂电极对O_(2)的电催化还原效果较好。80℃时制备的Pt∶Co=3∶1的Pt-Co/C催化剂电极对O_(2)的电催化还原效果最佳。扫描电子显微镜(Scanning Electron Microscope,SEM)和透射电子显微镜(Transmission Electron Microscope,TEM)观察表明,Pt-Co/C(1)催化剂粒径小且分散均匀。采用浸渍还原法,以硼氢化钠为还原剂制得的Pt-Co/C(1)催化剂对O2的电催化还原性能较好,同时具有较好的抗甲醇氧化能力。展开更多
Designing highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)plays a paramount importance for proton exchange membrane fuel cells.Pt-based binary alloys Pt-M(M=3d-transition metals)posses...Designing highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)plays a paramount importance for proton exchange membrane fuel cells.Pt-based binary alloys Pt-M(M=3d-transition metals)possessing excellent electronic and geometric properties have received increasing interests as highly active electrocatalysts.Herein,we report a series of Pt_(x)Co/C(x=1,2,3)catalysts by a facile one-pot soft-chemistry method.In the acidic conditions,the mass activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 0.526,0.462 and 0.441 A·mgPt^(-1),which are 2.60,2.31 and 2.22 times higher than that of Pt/C(0.200 A·mgPt^(-1)),respectively.The specific activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 706.59,679.41 and 801.83μA·cm^(-2),which are accordingly 2.89,2.76 and 3.28 times higher than that of Pt/C(244.75μA·cm^(-2)).Notably,Pt_(3)Co/C shows a remarkable durability.After 5000 cycles of the accelerated durability testing,the mass activity and specific activity of Pt_(3)Co/C catalyst are 2.47 and 3.80 times higher than that of the commercial Pt/C,respectively.The improved ORR activity and durability can be ascribed to the synergistic interaction between Pt and Co.展开更多
Photosynthesis[6CO_(2)+12H_(2)O→(CH_(2)O)+6O_(2)+6H_(2)O]in nature contains a light reaction process for oxygen evolution and a dark reaction process for carbon dioxide(CO_(2))reduction to carbohydrates,which is of g...Photosynthesis[6CO_(2)+12H_(2)O→(CH_(2)O)+6O_(2)+6H_(2)O]in nature contains a light reaction process for oxygen evolution and a dark reaction process for carbon dioxide(CO_(2))reduction to carbohydrates,which is of great significance for the survival of living matter.Therefore,for simulating photosynthesis,it is desirable to design and fabricate a bifunctional catalyst for promoting photocatalytic water oxidation and CO_(2)reduction performances.Herein,a molecular confined synthesis strategy is reasonably proposed and applied,that is the bifunctional CoO_(x)/Co/C-T(T=700,800 and 900℃)photocatalysts prepared by the pyrolysis of molecular Co-EDTA under N_(2) and air atmosphere in turn.Among the prepared photocatalysts,the CoOx/Co/C-800 shows the best photocatalytic water oxidation activity with an oxygen yield of 51.2%.In addition,for CO_(2)reduction reaction,the CO evolution rate of 12.6μmol/h and selectivity of 75%can be achieved over this catalyst.The improved photocatalytic activities are attributed to the rapid electron transfer between the photosensitizer and the catalyst,which is strongly supported by the current densityvoltage G-V,steady-state and time-resolved photoluminescence spectra(PL).Overall,this work provides a reference for the preparation and optimization of photocatalysts with the capacity for water oxidation and CO_(2)reduction reactions.展开更多
文摘为寻求一种较好的Pt-Co/C纳米合金催化剂合成方法,运用浸渍还原法制备两种Pt-Co/C催化剂,运用循环伏安和线性扫描的方法测试它们在H_(2)SO_(4)溶液中有无CH3OH时,对O_(2)的电催化还原情况及抗甲醇性能,同时与商用Pt/C催化剂进行还原性能比较。结果表明:与商用Pt/C催化剂电极相比,Pt-Co/C(1)催化剂电极对O_(2)的电催化还原效果较好。80℃时制备的Pt∶Co=3∶1的Pt-Co/C催化剂电极对O_(2)的电催化还原效果最佳。扫描电子显微镜(Scanning Electron Microscope,SEM)和透射电子显微镜(Transmission Electron Microscope,TEM)观察表明,Pt-Co/C(1)催化剂粒径小且分散均匀。采用浸渍还原法,以硼氢化钠为还原剂制得的Pt-Co/C(1)催化剂对O2的电催化还原性能较好,同时具有较好的抗甲醇氧化能力。
基金financially supported by the Project of National Natural Science Foundation of China(No.5202780089)。
文摘Designing highly active and durable electrocatalysts towards oxygen reduction reaction(ORR)plays a paramount importance for proton exchange membrane fuel cells.Pt-based binary alloys Pt-M(M=3d-transition metals)possessing excellent electronic and geometric properties have received increasing interests as highly active electrocatalysts.Herein,we report a series of Pt_(x)Co/C(x=1,2,3)catalysts by a facile one-pot soft-chemistry method.In the acidic conditions,the mass activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 0.526,0.462 and 0.441 A·mgPt^(-1),which are 2.60,2.31 and 2.22 times higher than that of Pt/C(0.200 A·mgPt^(-1)),respectively.The specific activities of PtCo/C,Pt_(2)Co/C and Pt_(3)Co/C are 706.59,679.41 and 801.83μA·cm^(-2),which are accordingly 2.89,2.76 and 3.28 times higher than that of Pt/C(244.75μA·cm^(-2)).Notably,Pt_(3)Co/C shows a remarkable durability.After 5000 cycles of the accelerated durability testing,the mass activity and specific activity of Pt_(3)Co/C catalyst are 2.47 and 3.80 times higher than that of the commercial Pt/C,respectively.The improved ORR activity and durability can be ascribed to the synergistic interaction between Pt and Co.
基金financially supported by the National Natural Science Foundation of China(No.22075119)the Natural Science Foundation of Gansu Province(No.21JR7RA440).
文摘Photosynthesis[6CO_(2)+12H_(2)O→(CH_(2)O)+6O_(2)+6H_(2)O]in nature contains a light reaction process for oxygen evolution and a dark reaction process for carbon dioxide(CO_(2))reduction to carbohydrates,which is of great significance for the survival of living matter.Therefore,for simulating photosynthesis,it is desirable to design and fabricate a bifunctional catalyst for promoting photocatalytic water oxidation and CO_(2)reduction performances.Herein,a molecular confined synthesis strategy is reasonably proposed and applied,that is the bifunctional CoO_(x)/Co/C-T(T=700,800 and 900℃)photocatalysts prepared by the pyrolysis of molecular Co-EDTA under N_(2) and air atmosphere in turn.Among the prepared photocatalysts,the CoOx/Co/C-800 shows the best photocatalytic water oxidation activity with an oxygen yield of 51.2%.In addition,for CO_(2)reduction reaction,the CO evolution rate of 12.6μmol/h and selectivity of 75%can be achieved over this catalyst.The improved photocatalytic activities are attributed to the rapid electron transfer between the photosensitizer and the catalyst,which is strongly supported by the current densityvoltage G-V,steady-state and time-resolved photoluminescence spectra(PL).Overall,this work provides a reference for the preparation and optimization of photocatalysts with the capacity for water oxidation and CO_(2)reduction reactions.
