Rapakousiou Amalia, Minadakis Michail P, Chalkidis Savvas G, Ruiz-González María Luisa, Navio Cristina, Vougioukalakis Georgios C, Tagmatarchis Nikos
Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens 11635, Greece.
Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771, Athens, Greece.
ACS Appl Mater Interfaces. 2025 May 14;17(19):28138-28150. doi: 10.1021/acsami.5c02182. Epub 2025 Mar 13.
In response to the need for sustainable energy, this study focuses on advancing the electrocatalytic Hydrogen Evolution Reaction (HER). Considering platinum-based catalysts' efficacy, but acknowledging their cost and scarcity implications, our work pursues Pt content minimization, simultaneously upholding catalytic efficiency. Our approach introduces a precisely engineered nanoarchitecture, leveraging multiwalled carbon nanotubes (MWCNTs) bearing anchored -heterocyclic carbenes (NHCs). These carbenes form robust covalent bonds with ultrastable, highly crystalline, platinum nanoparticles (PtNPs), establishing MWCNTs-NHC-PtNPs as a highly efficient electrocatalyst. The synergistic effect of NHCs and triazole moieties facilitates controlled nanoparticle growth and stabilization, yielding 2.0 ± 0.3 nm, uniformly distributed {1 1 1}-faceted PtNPs. The as-obtained MWCNTs-NHC-PtNPs nanomaterial exhibits exceptional HER efficiency in 0.5 M HSO with an overpotential of 77 mV at -10 mA cm and a 50 mV dec Tafel slope, despite containing a merely 0.4% Pt/C atomic ratio content, as determined by XPS. Notably, at 200 mV overpotential, the mass activity reaches 8.6 A/mg and the specific activity is 53 mA/cm, highlighting the efficiency of each Pt site within this nanostructure. Cyclic voltammetry reveals a distinctive, reversible PtO/Pt redox process, demonstrating surface-controlled and diffusion-assisted kinetics with charge storage properties that stabilize the electrocatalyst's electron-surface and facilitate proton reduction. Equally important, the nanoarchitecture prevents aggregation and mitigates Pt irreversible oxidation, showcasing enhanced stability after extensive cycling and exposure to air. Comparative analyses with a control electrocatalyst lacking NHC-PtNPs ligation emphasize the unique role of NHC-Pt (0) bonding in enhancing electrocatalytic efficiency. Comprehensive surface and electronic property analyses validate the potential of the MWCNTs-NHC-PtNPs platform.
为响应可持续能源的需求，本研究聚焦于推进电催化析氢反应（HER）。考虑到铂基催化剂的功效，但也认识到其成本和稀缺性问题，我们的工作致力于使铂含量最小化，同时保持催化效率。我们的方法引入了一种精确设计的纳米结构，利用负载锚定杂环卡宾（NHC）的多壁碳纳米管（MWCNT）。这些卡宾与超稳定、高度结晶的铂纳米颗粒（PtNP）形成牢固的共价键，将MWCNT-NHC-PtNP确立为一种高效的电催化剂。NHC和三唑部分的协同作用促进了纳米颗粒的可控生长和稳定，生成了尺寸为2.0±0.3纳米、均匀分布的{1 1 1}面的PtNP。通过XPS测定，所制备的MWCNT-NHC-PtNP纳米材料在0.5 M HSO中表现出卓越的HER效率，在-10 mA cm时过电位为77 mV，塔菲尔斜率为50 mV dec，尽管其Pt/C原子比含量仅为0.4%。值得注意的是，在200 mV过电位下，质量活性达到8.6 A/mg，比活性为53 mA/cm，突出了该纳米结构中每个铂位点的效率。循环伏安法揭示了一个独特的、可逆的PtO/Pt氧化还原过程，表明其具有表面控制和扩散辅助的动力学以及电荷存储特性，这些特性稳定了电催化剂的电子表面并促进质子还原。同样重要的是，该纳米结构可防止聚集并减轻铂的不可逆氧化，在长时间循环和暴露于空气中后仍表现出增强的稳定性。与缺乏NHC-PtNP连接的对照电催化剂的比较分析强调了NHC-Pt（0）键合在提高电催化效率方面的独特作用。全面的表面和电子性质分析验证了MWCNT-NHC-PtNP平台的潜力。
