Title: Shape-Controlled CO₂ Electrochemical Reduction on Nanosized Pd Hydride Cubes and Octahedra

Abstract

Electrochemical CO₂ reduction reaction (CO₂RR) provides a potential pathway to mitigate challenges related to CO₂ emissions. Pd nanoparticles have shown interesting properties as CO₂RR electrocatalysts, while how different facets of Pd affect its performance in CO₂ reduction to synthesis gas with controlled H₂ to CO ratios has not been studied. Herein, we synthesized nano-sized Pd cubes and octahedra particles dominated by Pd(100) and Pd(111) facets, respectively. Here, the Pd octahedra particles show higher CO selectivity (up to 95%) and better activity than Pd cubes and commercial particles. For both Pd octahedra and cubes, the ratio of H₂/CO products was tunable between 1 and 2, a desirable ratio for methanol production and the Fischer-Tropsch processes. Further studies of Pd octahedra in a 25-cm² flow cell showed a total CO current of 5.47 A was achieved at a potential of 3.4 V, corresponding to a CO partial current density of 220 mA/cm^-2. In situ X-ray absorption spectroscopy studies showed that regardless of facet Pd transformed into Pd hydride (PdH) under reaction conditions. DFT calculations show that the reduced binding energies of CO and HOCO intermediates on PdH(111) are key parameters to the high current density and Faradaic efficiency in CO₂ to COmore » conversion.« less

Authors:

Zhu, Wenlei  ^[1];

• Search DOE PAGES for author "Zhu, Wenlei"
• Search DOE PAGES for ORCID "0000-0002-3513-4354"

Kattel, Shyam ^[2]; Jiao, Feng  ^[1];

• Search DOE PAGES for author "Jiao, Feng"
• Search DOE PAGES for ORCID "0000-0002-3335-3203"

Chen, Jingguang G.  ^[2]

• Search DOE PAGES for author "Chen, Jingguang G."
• Search DOE PAGES for ORCID "0000-0002-9592-2635"

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+ Show Author Affiliations

1. Univ. of Delaware, Newark, DE (United States)
2. Columbia Univ., New York, NY (United States)

Publication Date:

Wed Jan 09 00:00:00 EST 2019

Research Org.:

Univ. of Delaware, Newark, DE (United States); Columbia Univ., New York, NY (United States)

Sponsoring Org.:

USDOE Office of Fossil Energy (FE); USDOE Office of Science (SC)

OSTI Identifier:

1712669

Alternate Identifier(s):

OSTI ID: 1490120

Grant/Contract Number:  

FE0029868; AC02‐06CH11357; FG02-13ER16381; SC0009476

Resource Type:

Accepted Manuscript

Journal Name:

Advanced Energy Materials

Additional Journal Information:

Journal Volume: 9; Journal Issue: 9; Journal ID: ISSN 1614-6832

Publisher:

Wiley

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; carbon dioxide; electrocatalysts; electrochemical reduction; CO2 reduction; density functional theory; free energy; Pd nanocrystals; syngas ratio