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Ammonium Formate as a Safe, Energy-Dense Electrochemical Fuel Ionic Liquid

Schiffer, Zachary J. and Biswas, Sayandeep and Manthiram, Karthish (2022) Ammonium Formate as a Safe, Energy-Dense Electrochemical Fuel Ionic Liquid. ACS Energy Letters, 7 (10). pp. 3260-3267. ISSN 2380-8195. doi:10.1021/acsenergylett.2c01826.

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While solid and liquid energy carriers are advantageous due to their high energy density, many do not meet the efficiency requirements to outperform hydrogen. In this work, we investigate ammonium formate as an energy carrier. It can be produced economically via a simple reaction of ammonia and formic acid, and it is safe to transport and store because it is solid under ambient conditions. We demonstrate an electrochemical cell that decomposes ammonium formate at 105 °C, where it is an ionic liquid. Here, hydrogen evolves at the cathode and formate oxidizes at the anode, both with ca. 100% Faradaic efficiency. Under the operating conditions, ammonia evaporates before it can oxidize; a second, modular device such as an ammonia fuel cell or combustion engine is necessary for complete oxidation. Overall, this system represents an alternative class of electrochemical fuel ionic liquids where the electrolyte is majority fuel, and it results in a modular release of hydrogen with potentially zero net-carbon emissions.

Item Type:Article
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URLURL TypeDescription
Schiffer, Zachary J.0000-0001-6069-8613
Manthiram, Karthish0000-0001-9260-3391
Additional Information:This material is based upon work supported by the Air Force Office of Scientific Research under award number FA9550-21-1-0194. The authors thank Venkat Viswanathan, Dilip Krishnamurthy, and Nikifar Lazouski for useful discussions. The authors thank Sharon Lin for help with the DSC measurements. Z.J.S. also acknowledges a graduate research fellowship from the National Science Foundation under Grant No. 1745302 and a fellowship from the MIT Energy Initiative, supported by Chevron.
Funding AgencyGrant Number
Air Force Office of Scientific Research (AFOSR)FA9550-21-1-0194
NSF Graduate Research FellowshipDGE-1745302
Massachusetts Institute of Technology (MIT)UNSPECIFIED
Issue or Number:10
Record Number:CaltechAUTHORS:20221006-438893200.2
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:117278
Deposited By: Research Services Depository
Deposited On:12 Oct 2022 23:42
Last Modified:07 Nov 2022 23:40

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