采用水热法和聚合物保护的硼氢化钠还原法制备了α-MnO_2及其负载Au-Pd的催化剂,考察了催化消除乙酸乙酯、间二甲苯及二者混合物的性能.XRD、SEM和TEM以及H2-TPR表征催化剂的物化性质.在反应物浓度为1000 mg/L,与O_2摩尔比为1:400,空速...采用水热法和聚合物保护的硼氢化钠还原法制备了α-MnO_2及其负载Au-Pd的催化剂,考察了催化消除乙酸乙酯、间二甲苯及二者混合物的性能.XRD、SEM和TEM以及H2-TPR表征催化剂的物化性质.在反应物浓度为1000 mg/L,与O_2摩尔比为1:400,空速为40000 m L/(g·h)的条件下,0.91Au0.48Pd/α-MnO_2比α-MnO_2的催化性能优越与其具有更好的低温还原性能有关.展开更多
Bimetallic palladium-gold （PdAu） catalysts have better catalytic performance than monometallic catalysts for many applications. PdAu catalysts with controlled nanostructures and enhanced activi- ties have been exten...Bimetallic palladium-gold （PdAu） catalysts have better catalytic performance than monometallic catalysts for many applications. PdAu catalysts with controlled nanostructures and enhanced activi- ties have been extensively studied but their syntheses require multiple and occasionally complicated steps, In this work, we demonstrated that supported PdAu catalysts could be simply prepared by doping a supported Pd catalyst with gold through wet impregnation and calcination. Resulting PdAu-on-carbon （PdAu/C） catalysts were tested for the room-temperature, aqueous-phase hydro- dech/orination of trichloroethene. The most active PdAu/C catalyst （Pd 1.0 wt%, Au 1.1 wt%, dried/air/H2 process] had an initial turnover frequency （TOF] of 34.0×10^-2 mOITcE mOled-1 S-1, which was 〉15 times higher than monometallic Pd/C （Pd 1,0 wt%, initial TOF of 2.2 ×10^-2 molTCE molpd^-1s^-1）. Through X-ray absorption spectroscopy, the gold kept Pd from oxidizing under calcination at 400℃. Probable nanostructure evolution pathways are proposed to explain the observed catalysis,展开更多
Less-expensive but efficient electrocatalysts are essential to accelerate the commercialization of fuel cells.Herein,ultrathin PdPb nanowires(PdPb NWs)with a diameter of around 3.5 nm were prepared by using a one-step...Less-expensive but efficient electrocatalysts are essential to accelerate the commercialization of fuel cells.Herein,ultrathin PdPb nanowires(PdPb NWs)with a diameter of around 3.5 nm were prepared by using a one-step hydrothermal method.The introduction of Pb in Pd-based bimetallic nanostructures produced high differences in the morphology from Pd nanoparticles(NPs)to various PdPb NWs.All the as-prepared PdPb NWs exhibited better electrocatalytic activity and durability than Pd NPs due to the synergistic effect.Especially,Pd65Pb35 possessed the highest current density of about 3460 mA mgPd^−1 for the ethanol electrooxidation which was around 6.3 times higher than commercial Pd/C.The high-performance of Pd65Pb35 is attributed to the defect-rich and stable nanowire structure with optimized surface atomic arrangement,as evidenced by high resolution transmission electron microscopy measurements and long-time treatment in an acidic media.The differences in the morphologies and electrocatalytic activities of PdPb NWs with varied Pb contents have also been discussed and analyzed.展开更多
文摘采用水热法和聚合物保护的硼氢化钠还原法制备了α-MnO_2及其负载Au-Pd的催化剂,考察了催化消除乙酸乙酯、间二甲苯及二者混合物的性能.XRD、SEM和TEM以及H2-TPR表征催化剂的物化性质.在反应物浓度为1000 mg/L,与O_2摩尔比为1:400,空速为40000 m L/(g·h)的条件下,0.91Au0.48Pd/α-MnO_2比α-MnO_2的催化性能优越与其具有更好的低温还原性能有关.
基金supported by the National Science Foundation,United States(EEC-0647452)the Welch Foundation(C-1676)~~
文摘Bimetallic palladium-gold （PdAu） catalysts have better catalytic performance than monometallic catalysts for many applications. PdAu catalysts with controlled nanostructures and enhanced activi- ties have been extensively studied but their syntheses require multiple and occasionally complicated steps, In this work, we demonstrated that supported PdAu catalysts could be simply prepared by doping a supported Pd catalyst with gold through wet impregnation and calcination. Resulting PdAu-on-carbon （PdAu/C） catalysts were tested for the room-temperature, aqueous-phase hydro- dech/orination of trichloroethene. The most active PdAu/C catalyst （Pd 1.0 wt%, Au 1.1 wt%, dried/air/H2 process] had an initial turnover frequency （TOF] of 34.0×10^-2 mOITcE mOled-1 S-1, which was 〉15 times higher than monometallic Pd/C （Pd 1,0 wt%, initial TOF of 2.2 ×10^-2 molTCE molpd^-1s^-1）. Through X-ray absorption spectroscopy, the gold kept Pd from oxidizing under calcination at 400℃. Probable nanostructure evolution pathways are proposed to explain the observed catalysis,
基金This work was financially supported by the National Natural Science Foundation of China(21773133)Taishan Scholars Advantageous and Distinctive Discipline Program for supporting the research team of energy storage materials of Shandong Province,China.
文摘Less-expensive but efficient electrocatalysts are essential to accelerate the commercialization of fuel cells.Herein,ultrathin PdPb nanowires(PdPb NWs)with a diameter of around 3.5 nm were prepared by using a one-step hydrothermal method.The introduction of Pb in Pd-based bimetallic nanostructures produced high differences in the morphology from Pd nanoparticles(NPs)to various PdPb NWs.All the as-prepared PdPb NWs exhibited better electrocatalytic activity and durability than Pd NPs due to the synergistic effect.Especially,Pd65Pb35 possessed the highest current density of about 3460 mA mgPd^−1 for the ethanol electrooxidation which was around 6.3 times higher than commercial Pd/C.The high-performance of Pd65Pb35 is attributed to the defect-rich and stable nanowire structure with optimized surface atomic arrangement,as evidenced by high resolution transmission electron microscopy measurements and long-time treatment in an acidic media.The differences in the morphologies and electrocatalytic activities of PdPb NWs with varied Pb contents have also been discussed and analyzed.
