Tailoring gas-phase CO₂ electroreduction selectivity to hydrocarbons at Cu nanoparticles

Abstract

Copper-based surfaces appear as the most active catalysts for CO electroreduction to hydrocarbons, even though formation rates and efficiencies still need to be improved. The aim of the present work is to evaluate the continuous gas-phase CO electroreduction to hydrocarbons (i.e. ethylene and methane) at copper nanoparticulated-based surfaces, paying attention to particle size influence (ranging from 25-80 nm) on reaction productivity, selectivity, and Faraday efficiency (FE) for CO conversion. The effect of the current density and the presence of a microporous layer within the working electrode are then evaluated. Copper-based gas diffusion electrodes are prepared by airbrushing the catalytic ink onto carbon supports, which are then coupled to a cation exchange membrane (Nafion) in a membrane electrode assembly. The results show that the use of smaller copper nanoparticles (25 nm) leads to a higher ethylene production (1148 μmol m s) with a remarkable high FE (92.8%), at the same time, diminishing the competitive hydrogen evolution reaction in terms of FE. This work demonstrates the importance of nanoparticle size on reaction selectivity, which may be of help to design enhanced electrocatalytic materials for CO valorization to hydrocarbons.

A Core–Shell‐Structured Silver Nanowire/Nitrogen‐Doped Carbon Catalyst for Enhanced and Multifunctional Electrofixation of CO2

“…[5,[29][30][31] Through controlling field-induced reagent concentration, [5] metal-nitrogen-carbons tructure, [32] or partially oxidized atomicc obalt layers, [33] the CO 2 adsorptionc apacity of catalysts could be increased, whichs equentially resulted in CO 2 enrichment aroundc atalysts despite the low CO 2 solubility in the electrolyte, [21] which enhances the activity for CO 2 electroreduction.I no ur research, CO 2 adsorption measurements of all catalysts were investigated at2 98 K (Figure 4b). [5,[29][30][31] Through controlling field-induced reagent concentration, [5] metal-nitrogen-carbons tructure, [32] or partially oxidized atomicc obalt layers, [33] the CO 2 adsorptionc apacity of catalysts could be increased, whichs equentially resulted in CO 2 enrichment aroundc atalysts despite the low CO 2 solubility in the electrolyte, [21] which enhances the activity for CO 2 electroreduction.I no ur research, CO 2 adsorption measurements of all catalysts were investigated at2 98 K (Figure 4b).…”

“…Besides ECSA, the differencesb etween CO 2 adsorptionc apacity might also be an explanation for the enhanced electrocatalytic activity.A ccording to former reports, CO 2 electroreduction always suffers from slow kinetics, owing to the low local concentration of CO 2 around typical CO 2 reduction catalysts. [5,[29][30][31] Through controlling field-induced reagent concentration, [5] metal-nitrogen-carbons tructure, [32] or partially oxidized atomicc obalt layers, [33] the CO 2 adsorptionc apacity of catalysts could be increased, whichs equentially resulted in CO 2 enrichment aroundc atalysts despite the low CO 2 solubility in the electrolyte, [21] which enhances the activity for CO 2 electroreduction.I no ur research, CO 2 adsorption measurements of all catalysts were investigated at2 98 K (Figure 4b). For AgNW/NC700, the CO 2 adsorptionc apacity at 298 Ka nd 1bar is 59.1 cm 3 g À1 at standard temperaturea nd pressure (STP), larger than the 50.6 cm 3 g À1 at STP for AgNW/ NC800 and 43.1 cm 3 g À1 at STP for AgNW/NC600.…”

One‐dimensional Nanomaterial Electrocatalysts for CO2Fixation

“…In 2015, Guo et al synthesized Cu-Pt alloys with different ratios of Cu/Pt for CO 2 electroreduction. [52] It was found that the alloying Cu with Pt allowed promoting the protonation of *CO key intermediate, leading to the enhancement for CH 4 .Y ang and co-workersr eported hierarchical CuSn nanowires with as urface alloy, [53] which decreased FEs for H 2 evolution from 55.7 %t o1 0.1 %a nd improved CO formation from 32.0 %t o9 0.0 %a tameasured potential of À0.8 Vv s. RHE. MacFarlane et al developed CuAu bimetallic NWs for CO 2 electroreduction.…”

“…As the ultimate carbon emission of the combustion process, carbon dioxide (CO 2 ) is a serious environmental threat in increasing the global climate temperature through the greenhouse effect . The global CO 2 atmospheric concentration has increased by ∼45 % from 280 ppm in the mid‐18th century to 406 ppm in 2017, including an increase of 6 ppm from 2015 to 2017 . Reducing the CO 2 level in the atmosphere is a crucial issue to alleviate the negative effects caused by global warming.…”

“…[1,2] The globalC O 2 atmosphericc oncentration has increased by~45 %f rom 280 ppm in the mid-18thc enturyt o 406 ppm in 2017, including an increaseo f6ppm from 2015 to 2017. [3,4] Reducing the CO 2 level in the atmosphere is ac rucial issue to alleviatet he negative effects caused by global warming. Electroreduction of CO 2 to hydrocarbons, ideally using excess electricity produced by renewable energy sources, may not only enablet he reduction of atmospheric CO 2 levels and subsequentglobal warming effect but also relieve our dependence on fossil fuels for sustainability.…”