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Exploring the impact of Nafion modifier on electrocatalytic CO_(2) reduction over Cu catalyst 被引量:1
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作者 Yingshi Su Yonghui Cheng +6 位作者 Zhen Li Yanjia Cui Caili Yang Ziyi Zhong Yibing Song Gongwei Wang Lin Zhuang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期543-551,I0012,共10页
Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Here... Nafion as a universal polymer ionomer was widely applied for nanocatalysts electrode preparation.However,the effect of Nafion on electrocatalytic performance was often overlooked,especially for CO_(2)electrolysis.Herein,the key roles of Nafion for CO_(2)RR were systematically studied on Cu nanoparticles(NPs)electrocatalyst.We found that Nafion modifier not only inhibit hydrogen evolution reaction(HER)by decreasing the accessibility of H_(2)O from electrolyte to Cu NPs,and increase the CO_(2)concentration at electrocatalyst interface for enhancing the CO_(2)mass transfer process,but also activate CO_(2)molecule by Lewis acid-base interaction between Nafion and CO_(2)to accelerate the formation of^(*)CO,which favor of C–C coupling for boosting C_(2)product generation.Owing to these features,the HER selectivity was suppressed from 40.6%to 16.8%on optimal Cu@Nafion electrode at-1.2 V versus reversible hydrogen electrode(RHE),and as high as 73.5%faradaic efficiencies(FEs)of C_(2)products were achieved at the same applied potential,which was 2.6 times higher than that on bare Cu electrode(~28.3%).In addition,Nafion also contributed to the long-term stability by hinder Cu NPs morphology reconstruction.Thus,this work provides insights into the impact of Nafion on electrocatalytic CO_(2)RR performance. 展开更多
关键词 Nafion modifier CO_(2)reduction cu nanoparticles In situ ATR-SEIRAS C_(2)product
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Cu single-atom electrocatalyst on nitrogen-containing graphdiyne for CO_(2) electroreduction to CH_(4)
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作者 Hao Dai Tao Song +8 位作者 Xian Yue Shuting Wei Fuzhi Li Yanchao Xu Siyan Shu Ziang Cui Cheng Wang Jun Gu Lele Duan 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第9期123-132,共10页
Developing Cu single-atom catalysts(SACs)with well-defined active sites is highly desirable for producing CH4 in the electrochemical CO_(2) reduction reaction and understanding the structure-property relationship.Here... Developing Cu single-atom catalysts(SACs)with well-defined active sites is highly desirable for producing CH4 in the electrochemical CO_(2) reduction reaction and understanding the structure-property relationship.Herein,a new graphdiyne analogue with uniformly distributed N_(2)-bidentate(note that N_(2)-bidentate site=N^N-bidentate site;N_(2)≠dinitrogen gas in this work)sites are synthesized.Due to the strong interaction between Cu and the N_(2)-bidentate site,a Cu SAC with isolated undercoordinated Cu-N_(2) sites(Cu1.0/N_(2)-GDY)is obtained,with the Cu loading of 1.0 wt%.Cu1.0/N_(2)-GDY exhibits the highest Faradaic efficiency(FE)of 80.6% for CH_(4) in electrocatalytic reduction of CO_(2) at-0.96 V vs.RHE,and the partial current density of CH_(4) is 160 mA cm^(-2).The selectivity for CH_(4) is maintained above 70% when the total current density is 100 to 300 mA cm^(-2).More remarkably,the Cu1.0/N_(2)-GDY achieves a mass activity of 53.2 A/mgCu toward CH4 under-1.18 V vs.RHE.In situ electrochemical spectroscopic studies reveal that undercoordinated Cu-N_(2) sites are more favorable in generating key ^(*)COOH and ^(*)CHO intermediate than Cu nanoparticle counterparts.This work provides an effective pathway to produce SACs with undercoordinated Metal-N_(2) sites toward efficient electrocatalysis. 展开更多
关键词 Carbon dioxide reduction ELECTROCATALYSIS cu single-atom catalyst N-containing graphdiyne Methane
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A dendritic Cu/Cu_(2)O structure with high curvature enables rapid and efficient reduction of carbon dioxide to C_(2) in an H-cell
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作者 Lei shao Bochen Hu +3 位作者 Jinhui Hao Junjie Jin Weidong Shi Min Chen 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第8期144-153,共10页
Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is chall... Electrocatalytic reduction of CO_(2)(CO_(2)RR)to multicarbon products is an efficient approach for ad-dressing the energy crisis and achieving carbon neutrality.In H-cells,achieving high-current C_(2)products is challenging because of the inefficient mass transfer of the catalyst and the presence of the hydrogen evolution reaction(HER).In this study,dendritic Cu/Cu_(2)O with abundant Cu^(0)/Cu^(+)interfaces and numerous dendritic curves was synthesized in a CO_(2)atmosphere,resulting in the high selectivity and current density of the C_(2)products.Dendritic Cu/Cu_(2)O achieved a C_(2)Faradaic efficiency of 69.8%and a C_(2)partial current density of 129.5 mA cm^(-2)in an H-cell.Finite element simulations showed that a dendritic structure with a high curvature generates a strong electric field,leading to a localized CO_(2)concentration.Additionally,DRT analysis showed that a dendritic struc-ture with a high curvature actively adsorbed the surrounding high concentration of CO_(2),enhancing the mass transfer rate and achieving a high current density.During the experiment,the impact of the electronic structure on the performance of the catalyst was investigated by varying the atomic ratio of Cu^(0)/Cu^(+) on the catalyst surface,which resulted in improved ethylene selectivity.Under the optimal atomic ratio of Cu^(0)/Cu^(+),the charge transfer resistance was minimized,and the desorption rate of the intermediates was low,favoring C_(2) generation.Density functional theory calculations indicated that the Cu^(0)/Cu^(+) interfaces exhibited a lower Gibbs free energy for the rate-determining step,enhancing C_(2)H_(4) formation.The Cu/Cu_(2)O catalyst also exhibited a low Cu d-band center,which enhanced the adsorption stability of *CO on the surface and facilitated C_(2)formation.This observa-tion explained the higher yield of C_(2) products at the Cu^(0)/Cu^(+) interface than that of H_(2) under rapid mass transfer.The results of the net present value model showed that the H-cell holds promising industrial prospects,contingent upon it being a catalyst with both high selectivity and high current density.This approach of integrating the structure and composition provides new insights for ad-vancing the CO_(2)RR towards high-current C_(2) products. 展开更多
关键词 reduction of CO_(2) High current Dendritic structure cu/cu_(2)O H-cell
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Achieving highly selective electrochemical CO_(2) reduction to C_(2)H_(4) on Cu nanosheets 被引量:1
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作者 Huan Xie Ruikuan Xie +6 位作者 Zhiyuan Zhang Yongyu Pang Yuting Luo Jiong Li Bilu Liu Maria-Magdalena Titirici Guoliang Chai 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第4期312-320,共9页
The conversion of CO_(2)into value-added chemicals coupled with the storage of intermittent renewable electricity is attractive.CuO nanosheets with an average size and thickness of~30 and~20 nm have been developed,whi... The conversion of CO_(2)into value-added chemicals coupled with the storage of intermittent renewable electricity is attractive.CuO nanosheets with an average size and thickness of~30 and~20 nm have been developed,which are in situ reduced into Cu nanosheets during electrochemical CO_(2)reduction reaction(ECO_(2)RR).The derived Cu nanosheets demonstrate much higher selectivity for C2H4production than commercial CuO derived Cu powder,with an optimum Faradaic efficiency of 56.2%and a partial current density of C_(2)H_(4)as large as 171.0 mA cm^(-2)in a gas diffusion flow cell.The operando attenuated total reflectance-Fourier transform infrared spectra measurements and density functional theory simulations illustrate that the high activity and selectivity of Cu nanosheets originate from the edge sites on Cu nanosheets with a coordinate number around 5(4–6),which facilitates the formation of^(*)CHO rather than^(*)COH intermediate,meanwhile boosting the C-C coupling reaction of^(*)CO and^(*)CHO intermediates,which are the critical steps for C_(2)H_(4)formation. 展开更多
关键词 Electrochemical CO_(2)reduction cu nanosheets C_(2)H_(4) High selectivity Coordination number
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Valence state effect of Cu on photocatalytic CO_(2)reduction
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作者 Fangxu Dai Mingming Zhang +2 位作者 Zhenjiang Li Jun Xing Lei Wang 《Materials Reports(Energy)》 EI 2023年第4期39-45,共7页
Copper(Cu)is extensively employed in photocatalytic CO_(2)reduction reactions for the production of high-value products.The valence state of transition metals plays a pivotal role in influencing the catalytic process.... Copper(Cu)is extensively employed in photocatalytic CO_(2)reduction reactions for the production of high-value products.The valence state of transition metals plays a pivotal role in influencing the catalytic process.However,due to the complex valence state changes of Cu in the CO_(2)reduction reaction,research on its valence state effect is lacking.The current work is to prepare a series of TiO_(2)/CuX with stable Cu valence composition using different copper halides(CuX and CuX_(2),X=Br or Cl)as precursors.The results show that the CuBr_(2)loading leads to Cu^(+)/Cu^(2+) mixed cocatalyst and exhibits the highest activity for CO_(2)photoreduction.The CH4 evolution rate of the TiO_(2)/CuBr_(2)catalyst is as high as 100.59μmol h^(-1)g^(-1),which is 6.6 times that of pristine TiO_(2).The CH4 selectivity reaches 77%.The enhanced catalytic activity and selectivity can be ascribed to the efficient surface adsorption,activation,excellent carrier separation,and transfer ofCu^(+)/Cu^(2+) mixed cocatalyst.Our findings provide a reference for designing highly active Cu-based photocatalysts. 展开更多
关键词 Valence state cu PHOTOCATALYTIC CO_(2)reduction
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Cu改性MIL-100(Fe)催化剂的SCR-C_(3)H_(6)脱硝特性
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作者 付维 宁淑英 +3 位作者 蔡晨 陈佳音 周皞 苏亚欣 《化工进展》 EI CAS CSCD 北大核心 2024年第9期4951-4960,共10页
烃类化合物选择性催化还原氮氧化物(SCR-HC)是一种很有发展前景的脱硝技术。催化剂有效的氧化-还原能力是影响其活性的关键因素。利用水热法制备了新型有机金属骨架MIL-100(Fe),通过超声浸渍法合成不同Cu含量的m Cu-MIL-100(Fe)催化剂,... 烃类化合物选择性催化还原氮氧化物(SCR-HC)是一种很有发展前景的脱硝技术。催化剂有效的氧化-还原能力是影响其活性的关键因素。利用水热法制备了新型有机金属骨架MIL-100(Fe),通过超声浸渍法合成不同Cu含量的m Cu-MIL-100(Fe)催化剂,在固定床微反应器中对其催化C_(3)H_(6)选择性还原NO的特性进行了实验研究。结果表明Cu的引入使MIL-100(Fe)催化活性得到改善。2.3Cu-MIL-100(Fe)的NO转化率在275℃下可达到100%,275~400℃范围内可维持85%以上NO转化率及90%以上N_(2)选择性,且具有较好抗SO_(2)的能力。通过各种技术手段对催化剂的微观结构及物化性质进行了表征,并对反应机理作了进一步讨论。N_(2)吸附-脱附结果表明,加入适量Cu可以增大催化剂的比表面积,并增强催化剂表面对反应气体的吸附能力;XPS研究结果表明,Cu可以提高催化剂表面的氧空位数目。Cu与Fe之间具有协同作用,二者之间存在电子转移现象。H_(2)-TPR曲线表明Cu使催化剂的还原特征峰向低温方向移动,增强了其还原性能。 展开更多
关键词 氮氧化物 选择催化还原 碳氢化合物 催化剂 cu改性 抗SO_(2)性能
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Preparation of Cu nanoparticles with ascorbic acid by aqueous solution reduction method 被引量:7
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作者 刘清明 Takehiro YASUNAMI +1 位作者 Kensuke KURUDA Masazumi OKIDO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第9期2198-2203,共6页
Cu nanoparticles were prepared by reducing Cu2+ ions with ascorbic acid through aqueous solution reduction method. The effects of solution pH and average size of Cu2O particles on the preparation of Cu nanoparticles ... Cu nanoparticles were prepared by reducing Cu2+ ions with ascorbic acid through aqueous solution reduction method. The effects of solution pH and average size of Cu2O particles on the preparation of Cu nanoparticles were investigated. Cu particles were prepared at pH 3, 5 or 7, with the smallest Cu particles obtained at pH 7. However, Cu particles could not be prepared at pH 9 or 11. The average size of Cu2O particles can affect that of Cu particles. Larger Cu2O particles result in larger Cu particles. In addition, experiments were conducted to explore the reaction process by measuring the X-ray diffraction (XRD) patterns of specimens collected at different time points during the reaction. It was found that Cu(OH)2 was initially formed as a precursor, followed by the formation of Cu2O, which was finally reduced to Cu particles. 展开更多
关键词 cu nanoparticles aqueous solution reduction method ascorbic acid intermediate product
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理论指导构建Cu-O-Ti-O_(v)活性位点及其高效电催化还原硝酸根研究
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作者 聂翼飞 颜红萍 +4 位作者 鹿苏微 张宏伟 齐婷婷 梁诗景 江莉龙 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第4期293-302,共10页
面向国家绿色低碳战略目标,变革化石资源合成氨技术路线变得尤为迫切,开发可再生能源制“绿氨”将成为合成氨领域未来的重要发展方向.将工业废水中的硝酸根(NO_(3)-)电催化还原为氨(NO_(3)RR),既可有效回收氨,又能消除硝酸根污染影响.然... 面向国家绿色低碳战略目标,变革化石资源合成氨技术路线变得尤为迫切,开发可再生能源制“绿氨”将成为合成氨领域未来的重要发展方向.将工业废水中的硝酸根(NO_(3)-)电催化还原为氨(NO_(3)RR),既可有效回收氨,又能消除硝酸根污染影响.然而,NO_(3)RR涉及缓慢的八电子转移过程,含有多种反应中间体,其反应机理复杂不明.此外,水系电解液中存在的析氢竞争反应也为高效NO_(3)RR催化剂的开发设计带来了巨大的挑战.为突破高效催化剂的发展瓶颈,本文通过理论模拟,在低成本的催化剂上设计了高效的NO_(3)RR催化活性位点,并利用简单的制备策略合成了目标催化剂.同时,结合原位表征技术,阐明了NO_(3)RR的反应路径及催化机理.本文通过密度泛函理论(DFT)计算发现,Cu/TiO_(2)催化剂上的Cu-O-Ti-O_(v)结构具有较好的NO_(3)-还原活性,该结构不仅能够促进反应中间体NOx-的吸附和活化,还能有效抑制竞争析氢反应,从而降低NO_(3)RR的反应能垒.在该结构上,NO_(3)RR的反应路径为:NO_(3)^(*)→NO_(2)^(*)→HONO^(*)→NO^(*)→*NOH→*N→^(*)NH→*NH2→*NH_(3)→NH_(3).基于理论计算结果,分别采用浸渍法和尿素水解法制备了系列富含Cu-O-Ti-O_(v)结构的Cu/TiO_(2)催化剂.氮气等温吸附-脱附曲线、拉曼光谱(Raman)、电子顺磁共振波谱、X射线光电子能谱(XPS)和傅立叶红外光谱等结果发现,相比于采用浸渍法制备的系列Cu/TiO_(2)催化剂,采用尿素水解法制备的Cu/TiO_(2)(CT-U)催化剂具有更大的比表面积以及更多的Cu-O-Ti-O_(v)位点,说明尿素水解法可提高Cu颗粒在TiO_(2)载体表面的分散度,增强Cu颗粒与TiO_(2)载体之间的相互作用,提高Cu/TiO_(2)催化剂表面的Cu-O-Ti-O_(v)位点含量.将以上制备出的催化剂应用于催化NO_(3)RR中,结果表明,在-1.0 V vs.RHE还原电位下,CT-U催化剂上氨产率可达3046.5μg h^(-1) mgcat^(-1),高于大多数文献报道结果.循环稳定性测试结果表明,在Cu/TiO_(2)催化剂上构建Cu-O-Ti-O_(v)位点还能显著抑制电催化反应过程中Cu物种从Cu/TiO_(2)催化剂上溶出,从而显著增强催化剂的稳定性.此外,设计制备了不含氧空位的Cu/TiO_(2),TiO_(2)-x,Cu,Cu_(2)O以及CuO催化剂,并将其用于催化NO_(3)RR.结果发现,上述催化剂上的氨产率皆明显低于CT-U催化剂,说明Cu,Ti以及O_(v)构成的Cu-O-Ti-O_(v)结构具有较好的催化协同作用,从而显著提升了NO_(3)RR反应活性.最后,通过原位Raman及原位XPS表征检测反应中间体,验证了由DFT模拟出的NO_(3)RR反应路径.综上,通过在Cu/TiO_(2)催化剂上理论指导构建Cu-O-Ti-O_(v)活性位点,实现了NO_(3)RR性能的有效提升.Cu-O-Ti-O_(v)结构中的多位点协同作用不仅促进了NO_(x)-的吸附和活化,而且抑制了电催化过程中Cu物种从催化剂上的溶出,从而提高了催化剂的稳定性.本研究为设计高效稳定的NO_(3)RR催化剂提供了新思路. 展开更多
关键词 电催化硝酸盐还原 合成氨 cu-O-Ti-O_(v)位点 协同催化 cu/TiO_(2)催化剂
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Effects of reaction parameters on preparation of Cu nanoparticles via aqueous solution reduction method with NaBH_4 被引量:1
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作者 刘清明 周德璧 +2 位作者 Yu-ya YAMAMOTO Kensuke KURUDA Masazumi OKIDO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第12期2991-2996,共6页
The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions f... The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions for preparing well-dispersed nanoparticles were found as follows: 0.4 mol/L NaBH4 was added into solution containing 0.2 mol/L Cu2+, 1.0% gelatin dispersant in mass fraction, and 1.2 mol/L NH3?H2O at pH 12 and 313 K. In addition, a series of experiments were performed to discover the reaction process. NH3?H2O was found to be able to modulate the reaction process. At pH=10, Cu2+ was transformed to Cu(NH3)42+ as precursor after the addition of NH3?H2O, and then Cu(NH3)42+ was reduced by NaBH4 solution. At pH=12, Cu2+ was transformed to Cu(OH)2 as precursor after the addition of NH3?H2O, and Cu(OH)2 was then reduced by NaBH4 solution. 展开更多
关键词 cu nanoparticles NABH4 cu(OH)2 cu(NH3)42+ aqueous solution reduction method PREcuRSOR reaction process
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Cu-Pd双金属电催化还原硝酸盐的研究进展
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作者 王伟 孙新阳 +5 位作者 朱向伟 程璐 周成瑞 周启立 谢陈鑫 钱光磊 《环境污染与防治》 CAS CSCD 北大核心 2024年第9期1378-1383,共6页
大量生活污水和工业废水排放导致地表水中硝酸盐污染加剧,对水生生态系统产生负面影响。而且,人体过量摄入硝酸盐会转化为亚硝酸盐,产生健康问题。因此,有必要对污(废)水中的硝酸盐进行去除。电催化还原技术是近年来兴起的硝酸盐去除技... 大量生活污水和工业废水排放导致地表水中硝酸盐污染加剧,对水生生态系统产生负面影响。而且,人体过量摄入硝酸盐会转化为亚硝酸盐,产生健康问题。因此,有必要对污(废)水中的硝酸盐进行去除。电催化还原技术是近年来兴起的硝酸盐去除技术,其中电极材料是影响电催化还原硝酸盐效果的重要因素。Cu-Pd双金属是当前最有潜力的电催化还原硝酸盐的阴极材料之一。阐述了Cu-Pd双金属电催化还原硝酸盐的机理,并从材料合成方法、载体优化及活性影响因素等角度进行了Cu-Pd双金属电极材料性能优化途径评述,总结了电催化还原硝酸盐过程中Cu-Pd双金属电极材料存在的问题及优化方向,旨在为后续Cu-Pd双金属电催化还原硝酸盐研究提供参考。 展开更多
关键词 cu-Pd双金属催化剂 电催化还原 硝酸盐 脱氮
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碳负载Cu-Bi双金属高效电催化CO_(2)还原制备乙醇
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作者 蒋瑞懿 付鑫 +3 位作者 蒲博 明瑞奇 吕骞 田丽红 《湖北大学学报(自然科学版)》 CAS 2024年第4期461-468,共8页
采用清洁电能驱动CO_(2)转化为碳氢燃料及高价值的化学品是实现“碳中和”最有应用前景的方式之一。在电催化还原CO_(2)的产物中,乙醇是极具吸引力的产物。Cu基催化剂具有良好电催化还原CO_(2)至C_(2+)产物的活性,但单一的Cu基催化剂不... 采用清洁电能驱动CO_(2)转化为碳氢燃料及高价值的化学品是实现“碳中和”最有应用前景的方式之一。在电催化还原CO_(2)的产物中,乙醇是极具吸引力的产物。Cu基催化剂具有良好电催化还原CO_(2)至C_(2+)产物的活性,但单一的Cu基催化剂不稳定,极易容易被氧化,因而可能严重降低电化学还原的电流密度及催化剂活性。本研究采用“一锅法”合成碳负载Cu-Bi双金属催化剂(Cu_(x)Bi_(y)@C)。在0.1 mol/L KCHO_(3)溶液中,CuxBiy@C表现出良好的电催化还原CO_(2)的活性,乙醇产物的选择性接近~100%。在-0.37 V(vs. RHE)过电位下CO_(2)还原为乙醇的法拉第效率可达到76.7%,其生成速率为450.6μmol g^(-1) h^(-1),催化剂在持续10 h的电催化还原过程中保持了良好的稳定性。动力学结果表明Cu、Bi双位点协同有利于质子/电子耦合转移,因而促进C-C偶联生成乙醇。 展开更多
关键词 cu-Bi催化剂 CO_(2)还原 电催化 乙醇
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Fe和Cu分子筛催化剂同时催化NO_(x)还原和N_(2)O分解
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作者 司庆宇 樊星 +2 位作者 张玮航 苗静文 刘若雯 《中国环境科学》 EI CAS CSCD 北大核心 2024年第9期4826-4834,共9页
采用离子交换法制备了Fe-Beta和Cu-SSZ-13催化剂并采用不同混合方式制备了复合催化剂,考察了催化剂同时催化NO_(x)还原和N_(2)O分解的性能.以实现NO_(x)和N_(2)O同时高效去除、拓宽活性温度窗口为目标,优选出了上Fe下Cu分层填充、Fe-Bet... 采用离子交换法制备了Fe-Beta和Cu-SSZ-13催化剂并采用不同混合方式制备了复合催化剂,考察了催化剂同时催化NO_(x)还原和N_(2)O分解的性能.以实现NO_(x)和N_(2)O同时高效去除、拓宽活性温度窗口为目标,优选出了上Fe下Cu分层填充、Fe-Beta和Cu-SSZ-13质量比为4:1的Fe_(0.4)Cu_(0.1)催化剂,进一步考察了进气组成对NO_(x)、N_(2)O和NH_(3)转化率的影响,并采用N_(2)吸脱附、XRD、NH_(3)-TPD、UV-Vis DRS和H_(2)-TPR等手段对催化剂理化特性进行了表征.结果表明,Cu-SSZ-13和Fe-Beta分别具有更优的催化NO_(x)还原和N_(2)O分解性能.采用Fe_(0.4)Cu_(0.1)催化剂、[NH_(3)]/[NO_(x)]为1时考察的温度范围内NH_(3)仅还原NO_(x),而N_(2)O通过分解去除,450℃时NO_(x)和N_(2)O转化率分别为93.4%和100%.高温(>350℃)下NH_(3)被O_(2)氧化导致NO_(x)转化率随温度升高而降低;高温(≥350℃)下N_(2)O分解形成的氧物种可使NO_(x)在进气中无O_(2)条件下实现高效还原.进气中含2%H_(2)O对高温(450℃)下Fe_(0.4)Cu_(0.1)表面NO_(x)的还原和NH_(3)的氧化无显著影响,但对N_(2)O的转化存在一定的可逆抑制作用.Cu-SSZ-13表面存在大量孤立的Cu^(2+)离子,可为NH_(3)-SCR反应提供充足的活性中心.Fe-Beta表面同时存在能够催化NO氧化的孤立Fe^(3+)离子和催化N_(2)O分解的Fe_(x)O_(y)物种.采用上Fe下Cu分层填充的混合方式时Fe-Beta表面NO氧化过程会消耗N_(2)O分解形成的氧物种,从而有利于低温(≤450℃)下N_(2)O的转化.但由于N_(2)O分解的温度范围内NO_(x)转化率本身较高,NO氧化对于脱硝的促进作用不显著. 展开更多
关键词 NO_(x)还原 N_(2)O分解 Fe-Beta cu-SSZ-13 复合催化剂
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Gliding arc discharge in combination with Cu/Cu_(2)O electrocatalysis for ammonia production
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作者 刘学 张佳伟 +5 位作者 何弈 黄嘉敏 马晓萍 张潇漫 卢曼婷 辛煜 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第7期67-73,共7页
Highly efficient and green ammonia production is an important demand for modern agriculture.In this study,a two-step ammonia production method is developed using a gliding arc discharge in combination with Cu/Cu_(2)O ... Highly efficient and green ammonia production is an important demand for modern agriculture.In this study,a two-step ammonia production method is developed using a gliding arc discharge in combination with Cu/Cu_(2)O electrocatalysis.In this method,NO_(x)is provided by the gliding arc discharge and then electrolyzed by Cu/Cu_(2)O after alkaline absorption.The electrical characteristics,the optical characteristics and the NO_(x)production are investigated in discharges at different input voltage and the gas flow.The dependence of ammonia production through Cu/Cu_(2)O electrocatalysis on pH value and reduction potential are determined by colorimetric method.In our study,two discharge modes are observed.At high input voltage and low gas flow,the discharge is operated with a stable plasma channel which is called the steady arc gliding discharge mode(A-G mode).As lowering input voltage and raising gas flow,the plasma channel is destroyed and high frequency breakdown occurs instead,which is known as the breakdown gliding discharge mode(B-G mode).The optimal NO_(x)production of 7.34 mmol h^(-1)is obtained in the transition stage of the two discharge modes.The ammonia yield reaches0.402 mmol h^(-1)cm^(-2)at pH value of 12.7 and reduction potential of-1.0 V versus reversible hydrogen electrode(RHE). 展开更多
关键词 gliding arc discharge nitrogen fixation cu/cu_(2)O catalyst electrocatalytic reduction of nitrite
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Y沸石中Cu(Ⅰ)的可控构筑及其乙烯/乙烷吸附分离性能研究
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作者 张凯博 沈佳新 +3 位作者 李玉霞 谈朋 刘晓勤 孙林兵 《化工学报》 EI CSCD 北大核心 2024年第4期1607-1615,共9页
乙烯(C_(2)H_(4))和乙烷(C_(2)H_(6))物理性质相似,其高效分离具有挑战性。利用Cu(Ⅰ)活性位与C_(2)H_(4)间的π络合作用,Cu(Ⅰ)基吸附剂能在温和条件下选择性地分离C_(2)H_(4)和C_(2)H_(6),显著降低传统低温精馏分离过程的能耗。Cu(Ⅰ)... 乙烯(C_(2)H_(4))和乙烷(C_(2)H_(6))物理性质相似,其高效分离具有挑战性。利用Cu(Ⅰ)活性位与C_(2)H_(4)间的π络合作用,Cu(Ⅰ)基吸附剂能在温和条件下选择性地分离C_(2)H_(4)和C_(2)H_(6),显著降低传统低温精馏分离过程的能耗。Cu(Ⅰ)由Cu(Ⅱ)还原制得,但Cu(Ⅱ)还原的不可控、能耗高且Cu(Ⅰ)收率低一直是Cu(Ⅰ)基吸附剂应用的障碍。采用选择性还原策略(SRS)成功在Y型沸石中选择性地构筑了Cu(Ⅰ)活性位,实现了温和条件下C_(2)H_(4)/C_(2)H_(6)的吸附分离。利用甲醛(HCHO)蒸气扩散传递,与沸石中的Cu(Ⅱ)反应,实现了低温(140℃)下Cu(Ⅰ)的选择性构筑;制得的Cu(Ⅰ)Y具有优异的C_(2)H_(4)/C_(2)H_(6)吸附分离性能,Cu(Ⅰ)Y的选择性达16.3,远高于Cu(Ⅱ)Y的3.2。机理研究表明,HCHO与Y沸石中的Cu(Ⅱ)发生氧化还原反应,在得到Cu(Ⅰ)的同时生成CO_(2)和H_(2)O。 展开更多
关键词 吸附 乙烯/乙烷分离 选择性 一价铜 选择性还原策略 沸石
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炭载Cu掺杂Mn_(3)O_(4)的氧还原催化活性与锌空气电池性能强化研究
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作者 张钧凯 诸葛祥群 +1 位作者 刘通 罗鲲 《现代化工》 CAS CSCD 北大核心 2024年第10期104-110,共7页
通过沉积-焙烧方法合成了一种在炭黑上Cu掺杂Mn_(3)O_(4)的氧还原反应(ORR)功能催化剂MCO/C。通过优化Mn与Cu的摩尔比合成得到Mn和Cu元素混合价态的MCO/C-51。在ORR过程中,MCO/C-51在Cu_(2)O/C、Mn_(3)O_(4)/C、MCO/C-31和MCO/C-71中表... 通过沉积-焙烧方法合成了一种在炭黑上Cu掺杂Mn_(3)O_(4)的氧还原反应(ORR)功能催化剂MCO/C。通过优化Mn与Cu的摩尔比合成得到Mn和Cu元素混合价态的MCO/C-51。在ORR过程中,MCO/C-51在Cu_(2)O/C、Mn_(3)O_(4)/C、MCO/C-31和MCO/C-71中表现出最佳的ORR催化活性,其Tafel斜率为73.6 mV/dec,电子转移数约为4.2,具有优异的循环稳定性。在锌-空气电池(ZABs)的阴极使用MCO/C-51催化剂,ZABs的循环寿命在5 mA/cm^(2)时超过128 h,其充放电容量也大幅提升,ZABs的比容量和功率密度分别达到691 mAh/(g Zn)和80 mW/cm^(2)。 展开更多
关键词 cu掺杂 Mn_(3)O_(4) 炭黑 氧还原催化剂 锌空气电池
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电催化还原CO_(2) Cu基催化剂研究进展
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作者 郭清霞 郭永乐 田俊英 《化工科技》 CAS 2024年第5期83-88,共6页
随着全球气候变化问题日益严重,电催化CO_(2)还原反应(ECO_(2)RR)作为一种将CO_(2)转化为高附加值燃料和化学品的方法受到了广泛关注。Cu作为一种ECO_(2)RR催化剂,能够高效催化CO_(2)电还原产生多种C+2产品,但是Cu催化剂在ECO_(2)RR中... 随着全球气候变化问题日益严重,电催化CO_(2)还原反应(ECO_(2)RR)作为一种将CO_(2)转化为高附加值燃料和化学品的方法受到了广泛关注。Cu作为一种ECO_(2)RR催化剂,能够高效催化CO_(2)电还原产生多种C+2产品,但是Cu催化剂在ECO_(2)RR中存在选择性差、稳定性差等问题。为了提高Cu催化剂的性能,通过杂原子修饰,缺陷构造,调控尺寸、形貌、晶面以及组成等策略对其进行了改性。对Cu基催化剂在ECO_(2)RR中的应用进行了综述,详细介绍了Cu基催化剂尺寸和形貌调控以及组成调控(如铜氧化物、双金属铜基催化剂、非金属掺杂)的设计策略,并分析了这些策略对Cu基电催化剂结构与性能的调控规律。 展开更多
关键词 CO_(2) cu基电催化剂 电催化还原
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MIL-125(Ti/Cu)有机框架的制备及其光催化还原CO_(2)的性能
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作者 宋微娜 穆美 +2 位作者 林俊康 邓忠员 刘亚敏 《黑龙江科技大学学报》 CAS 2024年第4期557-563,577,共8页
为改善环境污染、降低碳排放和缓解温室效应,设计合成了系列MIL-125(Ti/Cu)双金属有机框架催化剂,通过XRD、SEM、N_(2)吸附/脱附、FT-IR和TGA对样品进行了结构分析,研究了复合材料光催化还原CO_(2)性质。结果表明:助催化剂Cu掺杂可以获... 为改善环境污染、降低碳排放和缓解温室效应,设计合成了系列MIL-125(Ti/Cu)双金属有机框架催化剂,通过XRD、SEM、N_(2)吸附/脱附、FT-IR和TGA对样品进行了结构分析,研究了复合材料光催化还原CO_(2)性质。结果表明:助催化剂Cu掺杂可以获得结构稳定的Ti/Cu双金属MIL-125型金属有机框架材料,样品具有MOFs材料典型的大比表面积和多孔结构;Cu掺杂使复合材料分子吸收光谱向可见光区移动,增加了样品的电子转移效率;0.5-MCu样品光催化还原CO_(2)进行5 h,CO和CH 4的产量比MIL-125(Ti)增加一倍,分别为51.2和58.7μmol/g,光催化氧化还原过程中·OH和·O^(-)_(2)是主要的活性物种。 展开更多
关键词 Ti/cu双金属 MIL-125 金属有机框架 光催化还原CO_(2)
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高活性异质CuS/Mo_(6)S_(8)的构筑及其电催化硝酸根合成氨
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作者 谭子轩 杜沣 +1 位作者 佟梦棋 郭春显 《苏州科技大学学报(自然科学版)》 CAS 2024年第1期36-42,60,共8页
电化学还原硝酸根合成氨(NO_(3)^(-)RR)不仅有助于水中硝态氮污染物的去除,而且有助于缓解社会对氨能源的需求,减少污染,降低能耗。催化剂在一定程度上决定了NO_(3)^(-)RR的性能,然而,已报道的NO_(3)^(-)RR催化剂大多存在氨产率低和稳... 电化学还原硝酸根合成氨(NO_(3)^(-)RR)不仅有助于水中硝态氮污染物的去除,而且有助于缓解社会对氨能源的需求,减少污染,降低能耗。催化剂在一定程度上决定了NO_(3)^(-)RR的性能,然而,已报道的NO_(3)^(-)RR催化剂大多存在氨产率低和稳定性差等问题,设计和制备高性能和稳定性的NO_(3)^(-)RR催化剂是该领域的一个关键。论文设计和构筑了CuS/Mo_(6)S_(8)异质结构电催化剂,系统研究了其物化特性和NO_(3)^(-)RR性能,探讨了相关构效关系。实验结果表明,CuS/Mo_(6)S_(8)的法拉第效率和NO_(3)^(-)转化率分别为92.12%和91.34%,优于CuS(81.11%和74.13%)和Mo_(6)S_(8)(84.27%和80.23%),且经过连续4个循环(共12 h)NO_(3)^(-)RR测试,CuS/Mo_(6)S_(8)的各项性能均无明显衰减,展现出了优异的稳定性。分析和对比发现,该异质催化剂具有强的界面作用,通过Cu和Mo之间的电子转移改变了CuS/Mo_(6)S_(8)的电子结构,进而提升了NO_(3)^(-)RR性能。该研究提供了一种高性能和稳定性的NO_(3)^(-)RR催化剂,也可借鉴到设计其他高效异质催化剂。 展开更多
关键词 电化学还原硝酸根合成氨 cuS/Mo_(6)S_(8)异质结构 界面作用 活性位点 催化效率
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A Comparison of Hydrothermal Aging, SO2 and Propene Poisoning Effects on NH3-SCR over Cu-ZSM-5 and Cu-SAPO-34 Catalysts
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作者 Kouadio Brou Albert Koffi Konan Martin +1 位作者 Zran Van Eric-Simon Horo Kone 《Journal of Materials Science and Chemical Engineering》 2024年第5期10-28,共19页
This study was aimed to investigate the effects of hydrothermal aging, propene and SO<sub>2</sub> poisoning on the ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) performance of both... This study was aimed to investigate the effects of hydrothermal aging, propene and SO<sub>2</sub> poisoning on the ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) performance of both Cu-SAPO-34 and Cu-ZSM-5. The catalytic activities of fresh, aged and poisoned samples were tested in ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) of NO<sub>x</sub> conditions. The XRD, TG and N<sub>2</sub>-desorption results showed that the structures of the Cu-SAPO-34 and Cu-ZSM-5 remained intact after 750˚C hydrothermally aged, SO<sub>2</sub> and propene poisoned. After hydrothermal aging at 750˚C for 12 h, the NO reduction performance of Cu-ZSM-5 was significantly reduced at lower temperatures, while that of Cu-SAPO-34 was less affected. Moreover, Cu-SAPO-34 catalyst showed high NO conversion with SO<sub>2</sub> or propene compared to Cu-ZSM-5. However, Cu-ZSM-5 showed a larger drop in catalytic activity with SO<sub>2</sub> or propene compared to Cu-SAPO-34 catalyst. The H<sub>2</sub>-TPR results showed that Cu<sup>2 </sup> ions could be reduced to Cu<sup> </sup> and Cu<sup>0</sup> for Cu-ZSM-5, while no significant transformation of copper species was observed for Cu-SAPO-34. Meanwhile, the UV-vis DRS results showed that CuO species were formed in Cu-ZSM-5, while little changes were observed for the Cu-SAPO-34. Cu-SAPO-34 showed high sulfur and hydrocarbon poison resistance compared to Cu-ZSM-5. In summary, Cu-SAPO-34 with small-pore zeolite showed higher hydrothermal stability and better hydrocarbon and sulfur poison resistant than Cu-ZSM-5 with medium-pore. 展开更多
关键词 Hydrothermal Aging Propene and SO2Poisoning Ammonia-Selective Catalytic reduction(NH3-SCR) cu-SAPO-34 cu-ZSM-5
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Photocatalytic reduction of carbon dioxide to methanol by Cu_2O/SiC nanocrystallite under visible light irradiation 被引量:8
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作者 Huiling Li Yonggen Lei +4 位作者 Ying Huang Yueping Fang Yuehua Xu Li Zhu Xin Li 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2011年第2期145-150,共6页
The Cu2O/SiC photocatalyst was obtained from SiC nanoparticles (NPs) modified by Cu2O. Their photocatalytic activities for reducing CO2 to CH3OH under visible light irradiation have been investigated. The results in... The Cu2O/SiC photocatalyst was obtained from SiC nanoparticles (NPs) modified by Cu2O. Their photocatalytic activities for reducing CO2 to CH3OH under visible light irradiation have been investigated. The results indicated that besides a small quantity of 6H-SiC, SiC NPs mainly consisted of 3C-SiC. The band gaps of SiC and Cu2O were estimated to be about 1.95 and 2.23 eV from UV-Vis spectra, respectively. The Cu2O modification can enhance the photocatalytic performance of SiC NPs, and the largest yields of methanol on SiC, Cu2O and Cu2O/SiC photocatalysts under visible light irradiation were 153, 104 and 191μmol/g, respectively. 展开更多
关键词 photocatalytic reduction carbon dioxide heterogeneous catalysts SIC cu2O NANOPARTICLES
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