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Molecule aging induced by electron attacking
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作者 Ping Song Yining Dong +5 位作者 Xue Gong mingbo ruan Baoxin Ni Xuanhao Mei Kun Jiang Weilin Xu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期519-525,I0013,共8页
Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"... Here we propose a new concept of"molecule aging":with some special treatment,a molecule could be"aged"by losing some unknown tiny particles or pieces from atoms in the molecule,Such"aging"or loss of unknown tiny particles does not change apparently its molecular structure or chemical composition,but some physicochemical properties could be changed irreversibly.We further confirm such"molecule aging"via a long-term electron attacking to age water(H_(2)O)molecules.The IR spectra show no structural difference between the fresh water and the aged one,while the NMR spectra show that the electron attacking can decrease the size of water clusters.Such facts indicate that the electron attacking indeed can"affect"the structure of water molecule slightly but without damaging to its basic molecule frame.Further exploration reveals that the hydrogen evolution reaction(HER)activity of the aged water molecule is lower than the fresh water on the same Pt/C electrocatalyst.The density functional theory calculations indicate that the shortened O-H bond in H_(2)O indeed can present lower HER activity,so the observed size decrease of water clusters from NMR probably could be attributed to the shortening of O-H bond in water molecules.Such results indicate significantly that the molecule aging can produce materials with new functions for new possible applications. 展开更多
关键词 Aging of molecules Electron attacking Full width at half maxima Hydrogen evolution reaction
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基于数据挖掘对商业氧还原电催化剂Pt/C测试的综合分析
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作者 阮明波 刘京 +1 位作者 宋平 徐维林 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第1期116-121,共6页
近几十年来,聚合物电解质膜燃料电池(PEMFC)因其在零排放汽车、固定式和便携式发电设备中的应用而得到迅速发展.燃料电池的阴极氧还原反应(ORR)和阳极氢氧化反应(HOR)常用的催化剂为Pt基催化剂,因此整个燃料电池系统的成本高昂.而ORR的... 近几十年来,聚合物电解质膜燃料电池(PEMFC)因其在零排放汽车、固定式和便携式发电设备中的应用而得到迅速发展.燃料电池的阴极氧还原反应(ORR)和阳极氢氧化反应(HOR)常用的催化剂为Pt基催化剂,因此整个燃料电池系统的成本高昂.而ORR的反应速率比HOR慢得多,阴极上的Pt消耗量远高于阳极上.为了降低燃料电池Pt的用量,近年来,许多类型的非铂或低铂ORR电催化剂被报道作为传统Pt基催化剂的可能替代品,以降低成本促进燃料电池的大规模应用.为了评估新催化剂的ORR性能,一般来说,都是以最先进的商业Pt/C的ORR性能作为参考标准进行比较.最简单常用的方法是采用旋转盘电极测试技术,比较线性扫描曲线上极限扩散电流一半处的电位(半波电位E_(1/2)):半波电位越高,说明其ORR性能越好.众所周知,Pt/C催化剂的本征活性主要与其微观结构和组成有关,而不是与测试方案有关,理想情况下,不同实验室对相同类型的商用Pt/C的测量结果应该是相同的.然而,不同实验室采用的测试方案不同,所得的商业Pt/C的“表观”ORR性能差异巨大.显然,在不考虑不同实验室之间测试方案的微小差异的情况下,作为参比的Pt/C电催化剂的这种明显的性能差异使得来自不同实验室的不同催化剂之间的ORR性能的比较变得无序和不可靠.为解决此问题,需要一种标准的简单测试方案作为商业Pt/C甚至其他类型电催化剂的测试参考,以便在不同的实验室中获得易于重复的“表观”结果.本文通过对全球不同实验室的514篇参考文献进行数据挖掘并进行综合分析发现,同类型Pt/C参比的“表观”活性差异可能主要归因于测试方案的差异,如铂负载(μg/cm^(2))、玻碳电极的尺寸和线性扫描速率等.基于这些主要影响因素,本文重点分析了商业Pt/C的表观活性(E_(1/2))与测试方案中各因素之间的相关性.经初步分析发现,大部分测试采用非欧姆补偿和负向扫描(从高电位向低电位扫描),在此前提下,本文深入分析了酸性和碱性电解质溶液中Pt载量、电极尺寸、扫描速率以及不同生产厂家对Pt/C的E1/2的影响.结果发现,在直径为4 mm、Pt负载量为20μg/cm^(2)的玻碳工作电极上,以10 mV/s的扫描速率,在酸性和碱性电解质中都可以获得可靠的商业Pt/C最可重复的ORR催化性能(E_(1/2)=0.84±0.03 V),且在高氯酸中的E_(1/2)值比在硫酸中更高,并得到实验证实.本文结果可作为商业Pt/C的ORR半波电位的“黄金参考”,用于评估其他ORR催化剂在酸性和碱性电解液中的性能.这项工作为作为ORR性能参考标准的商业Pt/C的可靠测试提供了参考. 展开更多
关键词 氧还原反应 商业铂碳 深度分析 验证实验
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Nanocluster PtNiP supported on graphene as an efficient electrocatalyst for methanol oxidation reaction 被引量:4
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作者 Long Yang Guoqiang Li +10 位作者 Rongpeng Ma Shuai Hou Jinfa Chang mingbo ruan Wenbin Cai Zhao Jin Weilin Xu Guiling Wang Junjie Ge Changpeng Liu Wei Xing 《Nano Research》 SCIE EI CSCD 2021年第8期2853-2860,共8页
In this study,phosphorus doped graphene supported PtNiP nanocluster electrocatalyst(PtNiP/P-graphene)was successfully prepared via a simple hypophosphite-assisted co-reduction method.The improved anchoring force and i... In this study,phosphorus doped graphene supported PtNiP nanocluster electrocatalyst(PtNiP/P-graphene)was successfully prepared via a simple hypophosphite-assisted co-reduction method.The improved anchoring force and increased anchoring sites of graphene support result from phosphorus doping as well as size-confined growth effect of NaH_(2)PO_(2) leads to uniform dispersion of ultrafine PtNiP nanoclusters.Doped P also promotes the removal of CO-like intermediate by adjusting Pt electronic structure combining with alloyed Ni via electronic effects.As a result,the as-prepared PtNiP/P-graphene catalyst with more exposed active sites and optimized electronic structure of Pt alloy shows excellent electrocatalytic performances for methanol oxidation reaction(MOR)both in activity and durability in an acidic medium. 展开更多
关键词 nanocluster PtNiP/P-graphene uniformly disperse phosphorus doping methanol electrochemical oxidation
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