Citation:

CCS Chemistry:工作高效不疲劳,只须让催化剂动起来

[J]. CCS Chemistry, ;2020, 2(1): 31-41. doi: 10.31635/ccschem.020.201900065 shu

CCS Chemistry:工作高效不疲劳,只须让催化剂动起来

Figures(1)

  •         美国西北大学黄嘉兴教授、湖南大学周一歌教授及成都电子科技大学康毅进教授提出 “流动电催化”(Fluidized Electrocatalysis)策略,显著提高电催化剂的抗疲劳性能以及电催化反应的稳定性,甚至可以让很不稳定的催化剂达到持久稳定的催化效果。




       在电催化反应中,催化剂材料通常被粘附在电极,比如碳电极的表面,而后浸入电解液中进行长时间、连续的电化学反应(图1a)。电催化反应有一些普遍的疲劳机制,例如反应中间体可能导致催化剂表面中毒,催化剂颗粒在长时间的电化学“压力”下发生团聚、烧结、溶解或钝化等。另外,反应活性物种到催化剂表面的扩散受限也会导致催化电流衰减。催化剂疲劳会大大降低催化剂的工作效率,缩短其寿命,导致整个电化学体系性能下降。针对此问题,传统的策略是从催化剂本身出发调控其表面状态和化学成分,或通过改进催化剂载体材料来防止催化剂颗粒的聚集和脱落,然而由于催化剂疲劳机制多种多样、催化剂及其载体的材料、成分和结构也各不相同,这些针对于催化材料本身的解决方案往往只适用于特定的催化剂,不具有普适性。



    图1


       在电催化过程中,电极反应只有电子转移步骤需要依赖电极。然而在常规催化体系中,由于电极一直处于极化状态,这会对催化剂产生不必要的额外的电化学压力,从而导致其疲劳和性能衰减。基于以上思考并结合单颗粒电分析化学的进展,美国西北大学黄嘉兴教授、湖南大学周一歌教授及成都电子科技大学康毅进教授合作,提出“流动电催化”的新策略来提高电催化剂的抗疲劳性能(图1b):催化剂颗粒并非以传统方式固定在电极上,而是在电解液中流动。

       单个颗粒与电极碰撞时产生瞬态法拉第电流积累起来,输出连续、稳定、可随催化剂用量不断增大的电流。对每一个催化剂颗粒而言,电场只在粒子与电极发生碰撞时才会作用于粒子并驱动电子转移,从而极大地降低了电化学压力作用于催化剂颗粒上的时间尺度,抑制了许多常见的疲劳机制。同时,流动模型在空间和时间上将电子转移步骤从其它相对较慢的电极反应步骤(如物质传质过程)分开,使得电极反应不再受传质限制,因而,流动催化剂还将经历更快的反应动力学。

    图2

       该工作以最典型的Pt/C颗粒为模型催化剂,首先在碳微电极上分析了Pt/C单颗粒的析氧反应电化学行为(图2),如颗粒碰撞频率、碰撞时间尺度、单颗粒产生的催化电流强度等。随后证明流动催化模型的输出电流表现出随电极面积及催化剂颗粒浓度的增大而增加的特征,而固定催化模型的输出电流则随催化剂负载量的增加很快达到饱和。同时通过计算,发现由于传质更加有效,流动体系中单颗粒的电流效率比固定体系高出两到三个数量级。这也是为什么流动体系中单位时间内同时参加反应的催化剂颗粒数远远小于固定体系,却依然能达到与后者相差不大的电流输出的原因。


    图3

       随后,该工作以析氧反应(OER)(图3)、甲醇氧化反应(MOR)及析氢反应(HER)(图4)三个经典电催化反应为模型,验证了流动电催化策略的确可极大缓解一系列不同催化剂疲劳机理,如高过电位下催化剂颗粒的团聚与溶解、反应中间体的毒化、催化剂粉化及脱落等。在OER与MOR模型中,通过考察单个催化剂颗粒所贡献的法拉第电量,发现即使在单个流动Pt/C颗粒的贡献远远大于固定颗粒的情况下,前者的烧结程度也不明显,但后者却已经彻底烧结了。这表明在流动电催化反应中,催化剂颗粒的抗疲劳性能的确得到了提升。


    图4

       综上所述,该工作提出了流动电催化策略,将催化剂颗粒的工作模式由传统的长时间、连续性工作转变为轮流、间断性工作,避免了电化学压力的不断积累,同时,催化剂颗粒将经历更快的反应动力学并输出更高的电流效率,有利于抑制材料性能的衰减,提高催化剂长时间工作的稳定性。

       当然,该流动策略的操作方式不可避免会带来体积能量密度的局限,但仍然可付诸大型固定电源供给与大规模电合成等实际应用场景。同时,流动催化剂较固定催化剂具有更高的稳定性,且易于回收及再利用,因此长时间的工作成本将远远低于固定催化剂。衡量体积能量密度与成本,该策略与改善、发展新型催化剂的实践可结合并行,有望发展成一种普适的提高电催化体系总体性能及稳定性的简单、高效的新方法。

       该工作以封面文章形式发表在CCS Chemistry 2020年第一期,并于近期被美国化学会新闻周刊Chemical & Engineering News (C&EN)报道(https://cen.acs.org/synthesis/catalysis/Free-floating-electrocatalysts-outperform-tethered/98/web/2020/02)。牛津大学Richard G.Compton教授评价该工作为:“The work is groundbreaking in that it takes particle-impact experiments from the academic study of single nanoparticle electrocatalysis and suggests that they can be scaled up with considerable benefit.”

    文章详情:

    Fluidized Electrocatalysis

    Yi-Ge Zhou, Yijin Kang, and Jiaxing Huang

    Link: https://doi.org/10.31635/ccschem.020.201900065

    Citation: CCS Chem. 2020, 2, 31–41

     








  • 加载中
  • 加载中
    1. [1]

      Ruolin CHENGHaoran WANGJing RENYingying MAHuagen LIANG . Efficient photocatalytic CO2 cycloaddition over W18O49/NH2-UiO-66 composite catalyst. Chinese Journal of Inorganic Chemistry, 2024, 40(3): 523-532. doi: 10.11862/CJIC.20230349

    2. [2]

      Wenlong LIXinyu JIAJie LINGMengdan MAAnning ZHOU . Photothermal catalytic CO2 hydrogenation over a Mg-doped In2O3-x catalyst. Chinese Journal of Inorganic Chemistry, 2024, 40(5): 919-929. doi: 10.11862/CJIC.20230421

    3. [3]

      Kun WANGWenrui LIUPeng JIANGYuhang SONGLihua CHENZhao DENG . Hierarchical hollow structured BiOBr-Pt catalysts for photocatalytic CO2 reduction. Chinese Journal of Inorganic Chemistry, 2024, 40(7): 1270-1278. doi: 10.11862/CJIC.20240037

    4. [4]

      Zhanggui DUANYi PEIShanshan ZHENGZhaoyang WANGYongguang WANGJunjie WANGYang HUChunxin LÜWei ZHONG . Preparation of UiO-66-NH2 supported copper catalyst and its catalytic activity on alcohol oxidation. Chinese Journal of Inorganic Chemistry, 2024, 40(3): 496-506. doi: 10.11862/CJIC.20230317

    5. [5]

      Yubang Li Xixi Hu Daiqian Xie . The microscopic formation mechanism of O + H2 products from photodissociation of H2O. Chinese Journal of Structural Chemistry, 2024, 43(5): 100274-100274. doi: 10.1016/j.cjsc.2024.100274

    6. [6]

      Wen YANGDidi WANGZiyi HUANGYaping ZHOUYanyan FENG . La promoted hydrotalcite derived Ni-based catalysts: In situ preparation and CO2 methanation performance. Chinese Journal of Inorganic Chemistry, 2024, 40(3): 561-570. doi: 10.11862/CJIC.20230276

    7. [7]

      Yi YANGShuang WANGWendan WANGLimiao CHEN . Photocatalytic CO2 reduction performance of Z-scheme Ag-Cu2O/BiVO4 photocatalyst. Chinese Journal of Inorganic Chemistry, 2024, 40(5): 895-906. doi: 10.11862/CJIC.20230434

    8. [8]

      Bing LIUHuang ZHANGHongliang HANChangwen HUYinglei ZHANG . Visible light degradation of methylene blue from water by triangle Au@TiO2 mesoporous catalyst. Chinese Journal of Inorganic Chemistry, 2024, 40(5): 941-952. doi: 10.11862/CJIC.20230398

    9. [9]

      Yi Herng ChanZhe Phak ChanSerene Sow Mun LockChung Loong YiinShin Ying FoongMee Kee WongMuhammad Anwar IshakVen Chian QuekShengbo GeSu Shiung Lam . Thermal pyrolysis conversion of methane to hydrogen (H2): A review on process parameters, reaction kinetics and techno-economic analysis. Chinese Chemical Letters, 2024, 35(8): 109329-. doi: 10.1016/j.cclet.2023.109329

    10. [10]

      Qiangqiang SUNPengcheng ZHAORuoyu WUBaoyue CAO . Multistage microporous bifunctional catalyst constructed by P-doped nickel-based sulfide ultra-thin nanosheets for energy-efficient hydrogen production from water electrolysis. Chinese Journal of Inorganic Chemistry, 2024, 40(6): 1151-1161. doi: 10.11862/CJIC.20230454

    11. [11]

      Jingping HuJing Xu . Total synthesis of a putative yuzurimine-type Daphniphyllum alkaloid C14epi-deoxycalyciphylline H. Chinese Chemical Letters, 2024, 35(4): 108733-. doi: 10.1016/j.cclet.2023.108733

    12. [12]

      Hailang JIAHongcheng LIPengcheng JIYang TENGMingyun GUAN . Preparation and performance of N-doped carbon nanotubes composite Co3O4 as oxygen reduction reaction electrocatalysts. Chinese Journal of Inorganic Chemistry, 2024, 40(4): 693-700. doi: 10.11862/CJIC.20230402

    13. [13]

      Tong LiLeping PanYan ZhangJihu SuKai LiKuiliang LiHu ChenQi SunZhiyong Wang . Electrochemical construction of 2,5-diaryloxazoles via N–H and C(sp3)-H functionalization. Chinese Chemical Letters, 2024, 35(4): 108897-. doi: 10.1016/j.cclet.2023.108897

    14. [14]

      Bin FangJiaqi YangLimin WangHaoqin LiJiaying GuoJiaxin ZhangQingyuan GuoBo PengKedi LiuMiaomiao XiHua BaiLi FuLin Li . A mitochondria-targeted H2S-activatable fluorogenic probe for tracking hepatic ischemia-reperfusion injury. Chinese Chemical Letters, 2024, 35(6): 108913-. doi: 10.1016/j.cclet.2023.108913

    15. [15]

      Jia-Mei QinXue LiWei LangFu-Hao ZhangQian-Yong Cao . An AIEgen nano-assembly for simultaneous detection of ATP and H2S. Chinese Chemical Letters, 2024, 35(6): 108925-. doi: 10.1016/j.cclet.2023.108925

    16. [16]

      Ke-Ai Zhou Lian Huang Xing-Ping Fu Li-Ling Zhang Yu-Ling Wang Qing-Yan Liu . Fluorinated metal-organic framework for methane purification from a ternary CH4/C2H6/C3H8 mixture. Chinese Journal of Structural Chemistry, 2023, 42(11): 100172-100172. doi: 10.1016/j.cjsc.2023.100172

    17. [17]

      Jing Wang Zhongliao Wang Jinfeng Zhang Kai Dai . Single-layer crystalline triazine-based organic framework photocatalysts with different linking groups for H2O2 production. Chinese Journal of Structural Chemistry, 2023, 42(12): 100202-100202. doi: 10.1016/j.cjsc.2023.100202

    18. [18]

      Yudi ChengXiao WangJiao ChenZihan ZhangJiadong OuMengyao SheFulin ChenJianli Li . A near-infrared fluorescent probe for visualizing transformation pathway of Cys/Hcy and H2S and its applications in living system. Chinese Chemical Letters, 2024, 35(5): 109156-. doi: 10.1016/j.cclet.2023.109156

    19. [19]

      Zhenchun YangBixiao GuoZhenyu HuKun WangJiahao CuiLina LiChun HuYubao Zhao . Molecular engineering towards dual surface local polarization sites on poly(heptazine imide) framework for boosting H2O2 photo-production. Chinese Chemical Letters, 2024, 35(8): 109251-. doi: 10.1016/j.cclet.2023.109251

    20. [20]

      Xiaodan WangYingnan LiuZhibin LiuZhongjian LiTao ZhangYi ChengLecheng LeiBin YangYang Hou . Highly efficient electrosynthesis of H2O2 in acidic electrolyte on metal-free heteroatoms co-doped carbon nanosheets and simultaneously promoting Fenton process. Chinese Chemical Letters, 2024, 35(7): 108926-. doi: 10.1016/j.cclet.2023.108926

Metrics
  • PDF Downloads(0)
  • Abstract views(6585)
  • HTML views(659)

通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索
Address:Zhongguancun North First Street 2,100190 Beijing, PR China Tel: +86-010-82449177-888
Powered By info@rhhz.net

/

DownLoad:  Full-Size Img  PowerPoint
Return