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在室温下实现CO氧化对气体净化具有重要意义，但目前仍具有挑战性。三维过渡金属(TMs)促进的Pt是该反应的一个很有希望的候选物，但TMs容易在富氧环境中被深度氧化，导致活性降低。在此，我们报告了一种独特的石墨烯结构设计，从CoNi纳米颗粒（Pt|CoNi）中分离出Pt，用于在富氧气氛中高效催化CO的氧化。CoNi合金被超薄石墨烯保护以防止氧化，因此通过电子穿透效应调节Pt-石墨烯界面的电子性质。该催化剂在室温下可实现近100%的CO转化，而在Pt/C和Pt/CoNiOx催化剂上的转化率有限。实验和理论计算表明，CO会使Pt位饱和，而O2可以吸附在Pt-石墨烯界面上而不与CO竞争，这有利于O2的活化和随后的表面反应。这种石墨烯隔离体系不同于传统的金属-金属氧化物界面催化剂，为多相催化剂的设计提供了新的思路。 图1. 石墨烯包覆CoNi合金上Pt的结构表征和建模。(a) CoNi@NC的TEM图像。(b,c) Pt/CoNi@NC的TEM图像。(d) Pt/CoNi@NC的HAADF-STEM图像。(e) Pt/CoNi@NC和Pt/CoNi@C的XRD图。(f) Pt/CoNi@NC, Pt/CoNi@C, Pt/ CNT,和Pt/CB的Pt LIII边缘的XANES光谱。(g)根据XANES光谱计算每个催化剂中Pt的d-空穴数。(h)Pt4在石墨烯笼上的催化剂模型，内部有或没有CoNi NPs，以及相应的Pt4 Barder电荷（左侧列）和Pt4与石墨烯之间的结合能（右侧列）。(i)在Pt4/CoNi@C和Pt4/C中C原子2s+2p轨道的PDOS。(j) Pt4/CoNi@C和Pt4/C差分电荷密度的Top视图。红色和绿色区域分别表示电子的增加和损耗。 图2. 用于CO氧化的石墨烯包覆CoNi合金上Pt的结构-活性关系。(a)预还原催化剂上CO氧化反应中CO转化率的温度依赖性。He(1 bar)中的1% CO和20% O2。空速：60000 mL g-1h-1。(b) Pt/CoNi@NC表面NAP-XPS测试Co 2p3/2和Ni 2p3/2的XPS光谱,不同反应温度下的0.067 mbar CO和1.13 mbar O2。(c) 在特定温度下反应后Pt/CoNi@NC的TEM图像。(d) Pt/CoNi@NC表面CO氧化循环试验中CO转化率的温度依赖性. He（1 bar）中的1% CO和20% O2。空速：60000 mL g-1h-1。(e) Pt/CoNi@NC经过五个连续的原位反应过程的LEIS光谱。He（1 bar）中的1% CO和20% O2。空速：60000 mL g-1h-1.右表显示了这些阶段的催化剂中O与C的峰面积比。 图3. 石墨烯包覆CoNi合金上Pt催化CO氧化机理的DFT计算。(a)在Pt4/CoNi@C和Pt4/C上CO和O2的吸附能。(b)Pt4/CoNi@C（红线）和Pt4/C（蓝线）以及Pt4/CoNi@C的中间体结构上的CO氧化能曲线。“TS”表示过渡状态。(c)室温下电子穿透触发Pt-石墨烯的CO氧化界面活性示意图。红色、灰色、黄色、绿色和粉色的球分别代表O、C、Pt、Co和Ni。（步骤1：Pt-石墨烯界面上的O2吸附，步骤2：CO和O之间的表面反应，步骤3：Pt-石墨烯界面上的CO2释放）。 相关研究成果由固体表面物理化学国家重点实验室，能源材料化学协同创新中心，厦门大学化学与化工学院Yong Wang等人于2021年发表在Nature communications (https:///10.1038/s41467-021-26089-y)上。原文：Electron penetration triggering interface activity of Pt-graphene for CO oxidation at room temperature。 Yong Wang, Ph.D. Voiland Distinguished Professor 2008 Voiland School Alumni Awardee Development of novel catalytic materials and reaction engineering for the conversion of fossil and biomass feedstocks to fuels and chemicals. Biography Dr. Wang joined PNNL in 1994 and was promoted to Laboratory Fellow in 2005. He led the Catalysis and Reaction Engineering Team from 2000 to 2007, and has served as the Associate Director of the Institute for Integrated Catalysis (http://iic.) since 2008. In 2009, Dr. Wang assumed a joint position at Washington State University and PNNL. In this unique position, he continues to be a Laboratory Fellow and associate director of IIC at PNNL and is the Voiland Distinguished Professor in Chemical Engineering at WSU, full professorship with tenure. Dr. Wang is best known for his leadership in the development of novel catalytic materials and reaction engineering to address the issues related to energy and atom efficiency for converting fossil and biomass feedstocks to fuels and chemicals. Dr. Wang has authored 368 peer reviewed publications in lead scientific journals including Science, Nature group journals, J.Am.Chem.Soc, Angewandt Chemie, Energy and Env. Sci., ACS Catalysis, and the Journal of Catalysiswith H index=82 and has more than 31,000 citations. He has co-edited 2 books and 6 special journal issues, and given more than 180 invited presentations since 2001. He is the inventor on 283 issued patents including 110 issued U.S. patents (>90% of his patents are licensed to industries). His discoveries in microchannel reaction technologies led to the formation of Velocys, trading under the London Stock Exchange (VLS). He is a member of the Washington State Academy of Science. He is a fellow of: NAI (National Academy of Inventors), AIChE (American Institute of Chemical Engineers), ACS (American Society of Chemistry), RSC (Royal Society of Chemistry), and AAAS (American Association of the Advancement of Science). He has won numerous awards including the 2021 ACS E.V. Murphree Award in Industrial and Engineering Chemistry, 2019 AIChE Catalysis and Reaction Engineering Practice Award, the 2018 American Chemical Society I&EC Division Fellow Award, the 2006 Asian American Engineer of the Year Award, the Pre. |
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