In:
Green Chemistry, Royal Society of Chemistry (RSC), Vol. 23, No. 20 ( 2021), p. 8138-8146
Abstract:
Metal–CO 2 batteries represent a potential new technology for environmental protection, as they can effectively reduce CO 2 emissions while ensuring energy production. However, the design of active, selective, and cost-efficient electrocatalysts remains a challenge. Herein, we report two tubular cathodes (CNTs@Cu and CNTs@Ni, CNTs = carbon nanotubes) that are used to assemble two primary Zn–CO 2 flow batteries with zinc wire and 1-ethyl-3-methylimidazolium tetrafluoroborate as the anode and electrolyte, respectively. Interestingly, CO 2 conversion with quite high selectivity could be realized over the different cathodes in these two Zn–CO 2 flow batteries. These two batteries exhibit the advantages of high operating voltages, excellent stability, and continuous and selective product outputs. The flow battery based on the tubular CNTs@Cu cathode can convert CO 2 into CH 4 with a faradaic efficiency of up to 93.3%. Concurrently, electricity is generated at an energy density of 376 Wh kg −1 . This battery remains stable for more than 18 days. Surprisingly, the flow battery with a tubular CNTs@Ni cathode can reduce CO 2 to syngas (CO and H 2 , faradaic efficiencies for CO and H 2 of up to 50% and 48%, respectively) while generating electricity at an energy density of 208.7 Wh kg −1 , and it is stable for up to 9 days. These excellent performances are attributed to a synergistic effect involving CNTs and the metal substrate, and the differences between these two batteries are mainly ascribed to metal substrate effects. Excitingly, low concentrations of CO 2 released by humans and simulated vehicle emissions could also be converted. This work demonstrates that Zn–CO 2 flow batteries are green, selective, efficient, and promising devices for producing value-added chemicals, and they are worthy of further theoretical studies and practical application.
Type of Medium:
Online Resource
ISSN:
1463-9262
,
1463-9270
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2021
detail.hit.zdb_id:
1485110-6
detail.hit.zdb_id:
2006274-6
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