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AuthorNazir, Roshan
AuthorKumar, Anand
AuthorAli, Sardar
AuthorSaad, Mohammed A.
AuthorAl-Marri, Mohammed J.
Available date2020-04-09T07:35:00Z
Publication Date2019
Publication NameCatalysts
ResourceScopus
ISSN20734344
URIhttp://dx.doi.org/10.3390/catal9100860
URIhttp://hdl.handle.net/10576/13919
AbstractA bimetallic alloy of CoAg nanoparticles (NPs) on a carbon nitride (CN) surface was synthesized using a galvanic exchange process for the oxygen reduction reaction (ORR) and carbon dioxide electrocatalytic conversion. The reduction potential of cobalt is ([Co2+(aq) + 2e? ? Co(s)], ?0.28 eV) is smaller than that of Ag ([Ag+(aq) + e? ? Ag(s)], 0.80 eV), which makes Co(0) to be easily replaceable by Ag+ ions. Initially, Co NPs (nanoparticles) were synthesized on a CN surface via adsorbing the Co2+ precursor on the surface of CN and subsequently reducing them with NaBH4 to obtain Co/CN NP. The Co NPs on the surface of CN were then subjected to galvanic exchange, where the sacrificial Co atoms were replaced by Ag atoms. As the process takes place on a solid surface, only the partial replacement of Co by Ag was possible generating CoAg/CN NPs. Synthesized CoAg/CN bimetallic alloy were characterized using different techniques such as powder x-ray diffraction (PXRD), x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electron diffraction spectroscopy (EDS) to confirm the product. Both the catalysts, Co/CN and CoAg/CN, were evaluated for oxygen reduction reaction in 1M KOH solution and carbon dioxide conversion in 0.5 M KHCO3. In the case of ORR, the CoAg/CN was found to be an efficient electrocatalyst with the onset potential of 0.93 V, which is comparable to commercially available Pt/C having Eonset at 0.91 V. In the electrocatalytic conversion of CO2, the CoAg/CN showed better performance than Co/CN. The cathodic current decreased dramatically below ?0.9V versus Ag/AgCl indicating the high conversion of CO2. - 2019 by the authors. Licensee MDPI, Basel, Switzerland.
SponsorAcknowledgements: The authors would like to gratefully acknowledge financial support from Total Research & Technology Feluy (Grant Number: QUEX-CENG-TRT-17/18) in conducting this research. The statements made herein are solely the responsibility of the authors. The authors also wish to gratefully acknowledge the Gas Processing Centre (GPC) at Qatar University for carrying out XRD and XPS analysis, and the Central Laboratory Unit (CLU) at Qatar University for services related to electron microscopy.
Languageen
PublisherMDPI AG
SubjectAgCo catalyst
Carbon dioxide conversion
Carbon nitride
Galvanic exchange
Oxygen reduction reaction
TitleGalvanic exchange as a novel method for carbon nitride supported coag catalyst synthesis for oxygen reduction and carbon dioxide conversion
TypeArticle
Issue Number10
Volume Number9
dc.accessType Open Access


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