Title: Microfluidic, One-Batch Synthesis of Pd Nanocrystals on N-Doped Carbon in Surfactant-Free Deep Eutectic Solvents for Formic Acid Electrochemical Oxidation

Abstract

One of the grand challenges that impedes practical applications of nanomaterials is the lack of robust manufacturing methods that are scalable, cheap, and environmentally friendly. In this work, we address this challenge by developing a microfluidic approach that produces surfactant-free Pd nanocrystals (NCs) uniformly loaded on N-doped porous carbon in a one-batch process. The deep eutectic solvent (DES) prepared from choline chloride and ethylene glycol was employed as a novel synthesis solvent, and its extended hydrogen networks and abundant ionic species effectively stabilize Pd facets and confine nanocrystal sizes without using surfactants. The microreactors provide faster heat exchange and more uniform mass transport, which in combination with DES produced Pd NCs with better-defined shape and predominately exposed Pd (100) facet. Furthermore, we describe that the N-doped functional groups in porous carbon direct dense and uniform heterogeneous growth of Pd NCs in a one-batch process, thereby eliminating a separate catalyst deposition step that is often involved in conventional synthesis. The Pd NCs in the one-batch-produced Pd/C catalysts exhibited a size distribution of similar to ~13 ± 3.5 nm and a high ESCA of 46.0 m²/g and delivered 362 mA/mg for formic acid electrochemical oxidation with improved stability, demonstrating the unique potentialsmore » of microfluidic reactors and DES for the controllable and scalable synthesis of electrocatalyst materials for practical applications.« less

Authors:

Zhang, Hong ^[1]; Lu, Ke  ^[2];

• Search DOE PAGES for author "Lu, Ke"
• Search DOE PAGES for ORCID "0000-0001-8086-9686"

Li, Bomin ^[3]; Liu, Yuzi  ^[4];

• Search DOE PAGES for author "Liu, Yuzi"
• Search DOE PAGES for ORCID "0000-0002-8733-1683"

Su, Yuanhai  ^[5];

• Search DOE PAGES for author "Su, Yuanhai"
• Search DOE PAGES for ORCID "0000-0002-0718-301X"

Wang, Rongyue ^[4]; Cheng, Yingwen  ^[2]

• Search DOE PAGES for author "Cheng, Yingwen"
• Search DOE PAGES for ORCID "0000-0002-0778-5504"

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+ Show Author Affiliations

1. Shanghai Jiao Tong Univ. (China); Northern Illinois Univ., DeKalb, IL (United States)
2. Northern Illinois Univ., DeKalb, IL (United States)
3. Northern Illinois Univ., DeKalb, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
4. Argonne National Lab. (ANL), Argonne, IL (United States)
5. Shanghai Jiao Tong Univ. (China)

Publication Date:

Fri Aug 28 00:00:00 EDT 2020

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); Northern Illinois University; Shanghai Jiao Tong University (SJTU); Science and Technology Commission of Shanghai Municipality

OSTI Identifier:

1756839

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

ACS Applied Materials and Interfaces

Additional Journal Information:

Journal Volume: 12; Journal Issue: 38; Journal ID: ISSN 1944-8244

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; microfluidics; deep eutectic solvent; formic acid oxidation; nanocrystals; palladium