Nature Comm电催化OER：部分氧化的Pd与缺陷碳配位促进2电子氧化还原生成水

加州大学圣地亚哥分校、加州大学尔湾分校、卡尔加里大学、哥伦比亚大学

基于此，加州大学圣地亚哥分校Zheng Chen，加拿大卡尔加里大学Samira Siahrostami，布鲁克海文国家实验室Jingguang G. Chen，加州大学Huolin L. Xin报道了部分氧化的钯（Pdδ+）与氧官能化的碳之间的协同相互作用可以促进酸性电解质中的2e- ORR。作者通过简单的溶液浸渍法，将Pd3和Pd4团簇沉积在OCNT上，合成了一类含有Pd-O-C型配位的催化剂。

本文通过将非晶态Pdδ+团簇（Pd3δ+和Pd4δ+）溶液沉积在轻度氧化的碳纳米管（Pdδ+-OCNT）上所制备的电催化剂对H2O2的选择性接近100%。同时与OCNT相比，该催化剂的ORR起始电位正向偏移约320mV。实现了Pdδ+-OCNT的高质量活度（1.946 A mg-1，0.45 V）较高。EXAFS和DFT表明Pd团簇与附近含氧官能团之间的相互作用是2e-ORR高选择性和高活性的关键。

H2O2是最重要的化学品之一，其被广泛应用于纤维和纸张生产，化学合成，废水处理和采矿业。目前基于蒽醌氧化工业生产H2O2的方法需要改进，来显著降低能源消耗和有机废物的产生。除此之外，H2O2的化学不稳定性也为运输和存储带来了安全隐患。为了满足需求，通过选择性2电子氧还原反应（ORR）途径电化学生成H2O2是一种有效的替代途径。而实现这一过程的关键是开发高效、经济可行的高选择性和高活性电催化剂。

长期以来，人们一直研究将贵金属和合金（包括Au，Pt，Pd-Au，Pt-Hg，Ag-Hg和Pd-Hg）在酸性环境中作为2电子ORR的电催化剂。到目前为止，Pd-Hg核壳纳米颗粒是酸性环境下活性最高的催化剂。但是，Hg的高毒性阻碍了它的工业应用。Fe-N-C和Co-N-C被认为是更具成本效益的催化剂，但是其选择性需要显著提高。

这项工作通过调节活性金属和氧化的碳载体之间的相互作用，为开发高选择性ORR电催化剂提供了一条独特的途径。

图2：Pdδ+-OCNT和H-Pd-OCNT电催化剂中缺陷和官能团的表征

Raman spectra a and FTIR spectra b of 6.5 h OCNT, Pdδ+-OCNT and H-Pd-OCNT. Peak assignments are listed in the Supplementary Figure 7 

c The distribution of carbon element in different coordination environments for 6.5 h OCNT, Pdδ+-OCNT and H-Pd-OCNT measured by C1s XPS.

文章链接:

https://www.nature.com/articles/s41467-020-15843-3

导师简介:

Zheng Chen, Ph.D

Assistant Professor

Department of NanoEngineering

PhD, Chemical and Biomolecular Engineering, UCLA, 2012

(Adviser: Prof. Yunfeng Lu)

B.S., Chemical Engineering, Tianjin University, 2007

Postdoc, Chemical Engineering, Stanford University, 2016

(Adviser: Profs. Zhenan Bao & Yi Cui)

资料来源：http://zhengchen.eng.ucsd.edu/members

Huolin Xin

Assistant Professor of Physics & Astronomy

Huolin Xin graduated from the Physics Department of Cornell University in 2011 and joined University of California, Irvine in 2018. Prior to becoming a professor at UCI, he worked at Brookhaven National Laboratory as a scientific staff member and a principle investigator from 2013 to 2018. His primary field of expertise lies in developing novel 3-D, atomic-resolution, and in situ spectroscopic and imaging tools to probe the structural, chemical, and bonding changes of energy materials during chemical reactions or under external stimuli.

资料来源：https://sites.google.com/view/deepem/group-members 

• Jingguang G. Chen（陈经广）

1982年，本科毕业于南京大学；1982-1988 年，博士毕业于美国匹兹堡大学(University of Pittsburgh)；1990-1998 年，Exxon 公司科学家；1998-2010 年，美国特拉华大学( University of Delaware)副教授、教授。2012-至今，美国哥伦比亚化学工程教授。

研究兴趣：碳化物、双金属用于催化和电催化剂，研究手段上跨越模型单晶体系和负载型催化剂，并利于原位同步辐射技术以及理论计算关联活性--结构--电子结构。

• Samira Siahrostami

Assistant Professor, Department of Chemistry, University of Calgary

Dr. Samira Siahrostami received her PhD in Physical Chemistry from Shiraz University, Iran in 2011. She then joined Center for Atomic-scale Material Design (CAMd), Technical University of Denmark (DTU) between 2011-2013 as a postdoctoral researcher under supervision of Prof. Jan Rossmeisl. In 2014, Samira joined SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University working with Prof. Jens Nørskov first as a postdoctoral researcher (2014-2016), then as a staff research engineer (2016-2018). In October 2018, Samira joined University of Calgary as an assistant professor. Her research focuses on designing catalysts for electrochemical reactions, which are of importance for renewable energy technologies including:

(i)   oxygen electrocatalysis, including

- oxygen reduction reaction (ORR) for fuel cell and metal air batteries

- oxygen evolution reaction (OER) for synthesis of hydrogen

- electrochemical synthesis of hydrogen peroxide

(ii)  CO2 electrocatalysis for synthesis of valuable hydrocarbons.

版权声明:

1) 本文仅代表原作者观点，不代表本平台立场，请批判性阅读。

2) 本文内容若存在版权问题，请联系我们及时处理。

3) 如作者对该文章有误解误读，请联系我们进行修改，欢迎各位老师进行批评指正。

4) 本文版权归科学材料站公众号所有，翻版必究。

投稿请联系contact@scimaterials.cn